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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

At Poas Volcano, no eruption reported.
Seismic activity is similar, compared to yesterday.
Low frequency and low amplitude volcanic earthquakes (LP type) are frequently recorded.

Volcanic gas concentrations remain near detection levels (MultiGAS SO2<0.9 ppm; ExpoGAS SO2 <0.4ppm. Interestingly, the CO2/SO2 ratio rose and fell sharply from April 5-6, 2022.

Poas - 06.04.2022 / 06:38 - webcam Ovsicori

Poas - 06.04.2022 / 06:38 - webcam Ovsicori

Poas - evolution of the acid lake and the scar left by the explosion, respectively on 06.04 / 07:38, 08.04 / 11:56 & 13:56, and 10.04 / 14:17 - one click to enlarge the thumbnailsPoas - evolution of the acid lake and the scar left by the explosion, respectively on 06.04 / 07:38, 08.04 / 11:56 & 13:56, and 10.04 / 14:17 - one click to enlarge the thumbnails
Poas - evolution of the acid lake and the scar left by the explosion, respectively on 06.04 / 07:38, 08.04 / 11:56 & 13:56, and 10.04 / 14:17 - one click to enlarge the thumbnailsPoas - evolution of the acid lake and the scar left by the explosion, respectively on 06.04 / 07:38, 08.04 / 11:56 & 13:56, and 10.04 / 14:17 - one click to enlarge the thumbnails

Poas - evolution of the acid lake and the scar left by the explosion, respectively on 06.04 / 07:38, 08.04 / 11:56 & 13:56, and 10.04 / 14:17 - one click to enlarge the thumbnails

The volcanic edifice is experiencing a slight extension according to the GPS network On April 5, 2022, 1 day before the hydrothermal explosion that destroyed the NE subaerial orange Fumarole of the hyperacid lake (April 6, 2:30 a.m.), SENTINEL-5P/ TROPOMI detected a mass of SO2 gas of about 500 tons in total which seems to have been emitted jointly by the Poás volcano and the Turrialba volcano After the hydrothermal explosion in the Fumarola Naranja from April 6 to today, the subaerial fumaroles in the eastern sector of the crater and the subaquatic fumarole south of the hyperacid lake (Boca A or old dome) continue to degas vigorously A very active convection cell is observed in mouth A.

The hyperacidic lake changed color from whale green to milky gray after the April 6 explosion and remains gray to this day, suggesting homogenization of the lake by vigorous convective fumaroles.

In view of the April 6, 2022 hydrothermal explosion in Fumarola Naranja, persons approaching the vicinity of the PNVP Visitor Lookout are advised to take precautions and follow the recommendations of the PNVP administration protocol.

Turrilaba - 05.04.2022 / 05:40 - webcam Ovsicori

Turrilaba - 05.04.2022 / 05:40 - webcam Ovsicori

At Turrialba Volcano, no rash reported.
Seismic activity is similar, compared to yesterday.
Seismicity is maintained with frequent low-frequency volcanic earthquakes and frequent short-duration, low-amplitude, broad-band-frequency tremors.

Regarding the gases emitted by the volcano, the concentration of SO2 gas remains below 10 parts per million, while the other gases measured remain at low and stable concentrations. On April 7, 2022, the temperature of the most visible fumaroles of the western crater was measured remotely with an infrared thermal camera, recording at least 115 degrees Celsius (I. Godfrey Global Business BS Management). The volcanic edifice is experiencing a slight extension according to the GPS network.

 

Sources: Ovsicori-UNA

Turrialba - temperature of the fumaroles on 07.04.2022: 115°C - Doc. I. Godfrey Global Business BS Management / via Ovsicori

Turrialba - temperature of the fumaroles on 07.04.2022: 115°C - Doc. I. Godfrey Global Business BS Management / via Ovsicori

Shane Cronin, a volcanologist at the University of Auckland, in April traversed and sampled, with his team, the Hunga Tonga-Hunga Haapai (HTHH) caldera after the mid-January 2022 eruptions

Little change on the coast, but the first 30 to 100 meters of cover deposits were stripped away by the explosion - leaving only lavas and clumps about 2000 years old.

Hunga Tonga- Hunga Haapai - eruption of 14.01.2022 / 5:14 p.m. - photo Taaniela Kula - TGS

Hunga Tonga- Hunga Haapai - eruption of 14.01.2022 / 5:14 p.m. - photo Taaniela Kula - TGS

Bathymetries of HTHH, with the 2009, 2014-2015 calderas (Doc. AGU's Eos), and geochemistry of the 2009, 2014-15 and older eruptions of HungaTongaHungaHaapai, by Dr. Marco Brenna (U. Otago). - one click to enlarge thumbnailsBathymetries of HTHH, with the 2009, 2014-2015 calderas (Doc. AGU's Eos), and geochemistry of the 2009, 2014-15 and older eruptions of HungaTongaHungaHaapai, by Dr. Marco Brenna (U. Otago). - one click to enlarge thumbnails
Bathymetries of HTHH, with the 2009, 2014-2015 calderas (Doc. AGU's Eos), and geochemistry of the 2009, 2014-15 and older eruptions of HungaTongaHungaHaapai, by Dr. Marco Brenna (U. Otago). - one click to enlarge thumbnails

Bathymetries of HTHH, with the 2009, 2014-2015 calderas (Doc. AGU's Eos), and geochemistry of the 2009, 2014-15 and older eruptions of HungaTongaHungaHaapai, by Dr. Marco Brenna (U. Otago). - one click to enlarge thumbnails

A nice section was discovered on the outer flanks of Hunga Ha'apai. The red top (thickening to the right) is a welded AD1150 pyroclastic flow deposit, capping unwelded gray deposits from the same eruption. Below are yellow AD200 deposits and older pyroclastic flow units on older lava flows.

Hunga Ha'apai, the outer flanks - photo Shane Cronin / 10.04.2022

Hunga Ha'apai, the outer flanks - photo Shane Cronin / 10.04.2022

The deposits from the January 2022 tsunami were inventoried on April 6: after analysis, 3 layers of slightly different grain size can be distinguished: the incoming wave (clean sand), a decline, then the outgoing wave (sand + debris and torn soil) - plus a thin black layer of ash near the summit, west of Tongatapu

 

Source : for details, see the Shane Cronin's Twitter page, volcanologist / Un. Auckland.

HTHH - section in tsunami and ash deposits - Doc. and explanation by Shane Cronin /11.04.2022 - one click to enlarge
HTHH - section in tsunami and ash deposits - Doc. and explanation by Shane Cronin /11.04.2022 - one click to enlarge

HTHH - section in tsunami and ash deposits - Doc. and explanation by Shane Cronin /11.04.2022 - one click to enlarge

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