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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 - alert level: vigilance - photo archives Bernard Duyck

Piton de La Fournaise - alert level: vigilance - photo archives Bernard Duyck

Since August 28, 2022 an increase in seismicity has been observed under the Piton de la Fournaise.

Thus 20 volcano-tectonic earthquakes were recorded on August 28, 24 on August 29 and 41 on August 30. These low magnitude earthquakes (<1) are located under the Dolomieu crater between 1.5 and 2.5 km deep.

Histogram representing the number of superficial volcano-tectonic earthquakes recorded since August 1, 2022 (Doc. © OVPF 31.08.2022)


This seismicity follows more than 7 months of inflation of the base and top of the Piton de la Fournaise building.

This inflation is linked to a pressurization of the superficial magmatic reservoir located at about 1.5-2 km depth.

The appearance of seismicity at the roof of the reservoir shows that this pressurization process is intensifying.

It should be noted that this process of recharging the superficial reservoir can last several days to several weeks before the roof of the reservoir weakens and does not rupture, thus giving rise to an injection of magma towards the surface and an eruption, but can also stop without giving rise - in the short term - to an eruption.

Alert level : Vigilance

 

Source: OVPF press release of 31.085.2022 / 09:00 local time

Kilauea / Halema 'um'u - HVO webcam 2022.08.30 / 05:48 - one click to enlarge

Kilauea / Halema 'um'u - HVO webcam 2022.08.30 / 05:48 - one click to enlarge

Kilauea / Halema 'um'u active lava lake - HVO webcam 2022.08.30 / 05:46 - one click to enlarge

Kilauea / Halema 'um'u active lava lake - HVO webcam 2022.08.30 / 05:46 - one click to enlarge

Lava eruption from the west vent into the active lava lake and floor of Kilauea's Halema'uma'u crater has continued over the past 24 hours. The active part of the lava lake showed continued surface activity. Surface activity, outside the lava lake, sometimes occurs from eruptions along the crater margins.

Summit tiltmeters recorded relatively little ground deformation over the past 24 hours. Volcanic tremor remains above background levels. A sulfur dioxide emission rate of approximately 1,400 tonnes per day (t/d) was measured on August 26, 2022.

 

Current volcanic alert level: Watch / Aviation code: Orange

 

Source: HVO

Whakaari / White island - gas plume accentuated by weather conditions on 31.08.2022 / 10:40 NZST - Inst. of Geological and Nuclear sciences Ltd.

Whakaari / White island - gas plume accentuated by weather conditions on 31.08.2022 / 10:40 NZST - Inst. of Geological and Nuclear sciences Ltd.

Whakaari / White island - fumaroles on the shores of the lake - photo Brad Scott31.08.2022 - one click to enlarge

Whakaari / White island - fumaroles on the shores of the lake - photo Brad Scott31.08.2022 - one click to enlarge

Thanks to GeoNet surveillance cameras, located at Whakatane, large plumes of steam and gas were observed from White island this morning, but the volcano remains quiet: no evidence of activity since the last flight.
It is common to see larger steam and gas plumes from Whakaari/White Island when atmospheric conditions are ideal.

 

Sources: GeoNet & Bras Scott

Vulcano - weak fumaroles on 08.30.2022 / 4:24 p.m. - VLVH / INGV webcam - one click to enlarge

Vulcano - weak fumaroles on 08.30.2022 / 4:24 p.m. - VLVH / INGV webcam - one click to enlarge

At La Fossa crater of  Vulcano, along the upper edge, temperatures remain stable at high values, averaging 373°C.
The CO2 flux in the crater area remains stable at medium-high values.

Data from the VSCS station for the past week show almost stable values ​​of CO2 fluxes which are around 7250 g/m2/day (weekly average), with a maximum daily peak of 10532 g/m2/day on 27/ 08 / 2022. The monthly average for the month of August is 8140 g/m2/day, in line with the month of July (8162 g/m2/day) and still abnormal compared to the average bottom values ​​evaluated on the last decade of observation and monitoring.

Vulcano - average soil CO2 flux over 1 year and 5 years - Doc. INGV OE 30.08.2022 - one click to enlarge

Vulcano - average soil CO2 flux over 1 year and 5 years - Doc. INGV OE 30.08.2022 - one click to enlarge

The CO2 flux at the base of the La Fossa cone and in the Vulcano Porto area: Flux values ​​stable and above the background noise of the Rimessa site. There is a slight upward trend at the Camping Sicilia site; values ​​reaching high levels at the Palizzi site. In the Faraglione site, stable values ​​close to the bottom.

The flow of SO2 in the crater area is at an average level
Geochemistry of thermal aquifers: in the waters of the Camping Sicilia well there are stable and always high temperature values ​​and medium-low conductivity values; in the Bambara well, the level and conductivity values, which are at average values, have undergone sudden changes, attributable to intense rainfall events.
Local seismicity remains low rate of occurrence of local events.
Regional seismicity: Poor fracturing seismicity associated with earthquakes with Ml >= 1.0.
The networks of permanent GNSS and clinometric stations have not registered any significant changes.

 

Source: INGV OE weekly bulletin

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