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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, #Sismologie
 Turrialba - 28.02.2019 / 11:00 - webcam Ovsicori

Turrialba - 28.02.2019 / 11:00 - webcam Ovsicori

In Turrialba / Costa Rica, an eruption occurred on February 28 from 10:50 local; it lasted 4 minutes and was accompanied by an ash plume 500 meters above the crater.

The seismic activity remains in the norms of the previous days.

Source: Ovsicori.

Nevados de Chillan - 28.02.2019 / 15:49 - webcam Sernageomin

Nevados de Chillan - 28.02.2019 / 15:49 - webcam Sernageomin

In Chile, Sernageomin provides whitish pulsatile emissions of water vapor, interspersed by grayish plume times due to the micro-particle content at Nevados de Chillan.

This activity remains in the context of a minor eruption, in relation to the construction-destruction cycles of the dome.

The alert level remains in Naranja.

 Peteroa - 27.02.2019 / 11h13 - photo CNEA SEGEMAR

 Peteroa - 27.02.2019 / 11h13 - photo CNEA SEGEMAR

Also in Chile, the level of emissions of Peteroa, of gas and particles, seems to have dropped a little in late February.

The system remains open at the top; alert level remains in Amarillo

Sources: Sernageomin and CNEA-SEGEMAR

 

At Piton de La Fournaise, despite slight fluctuations in intensity since February 25, the eruptive tremor remained relatively constant for several days.

Piton de La Fournaise - Evolution of the RSAM (indicator of the volcanic tremor and the intensity of the eruption) between 09h48 (05h48 UTC) on February 18th and 16h00 (12h00 UTC) on February 28th on the seismic station of FLR. (© OVPF / IPGP)

Piton de La Fournaise - Evolution of the RSAM (indicator of the volcanic tremor and the intensity of the eruption) between 09h48 (05h48 UTC) on February 18th and 16h00 (12h00 UTC) on February 28th on the seismic station of FLR. (© OVPF / IPGP)

Over the last 36 hours, 3 superficial volcano-tectonic earthquakes (above sea level) have been recorded.

After a deflation of the building related to magma transfer that occurred on 18/02/2019, the deformations of the summit zone do not show any particular signals.

The CO2 concentrations in the near field soil (volcano deposit area) remain high.

Over the last 36 hours, surface flows estimated from satellite data, via the HOTVOLC platform (OPGC - University of Auvergne), fluctuated between <1 and 16 m3 / s. Note that low values ​​(or zero values) are recorded when cloud cover does not allow acquisition.

A mapping of the lava flow dated 28/02/2018 carried out by the OI2 platform (OPGC - Clermont Auvergne University) using satellite data confirmed the slow progression of the lava flow (300 m in 5 days). The casting front is located 1200m above sea level and only the north arm is currently active.

 

Contours of the lava flows associated with the eruptive episode of 19/02/2019 determined from satellite data by the platform OI2 (University Clermont Auvergne), dated 20 (green), 21 (red), 22 (blue) , 27 (turquoise) and 28/02/2019 (pink).

 

Source: OVPF & Mirova

Find all the information related to the Piton de la Fournaise activity on the different media of the OVPF-IPGP:
- the website (http://www.ipgp.fr/fr/ovpf/actualites-ovpf),
- the Twitter account (https://twitter.com/obsfournaise?lang=en),
- and the facebook account (https://www.facebook.com/ObsVolcanoPitonFournaise/)

Piton de la Fournaise - thermal anomalies on 28.02.2019 / 22:15 - Doc. Mirova_MODIS_VRP

Piton de la Fournaise - thermal anomalies on 28.02.2019 / 22:15 - Doc. Mirova_MODIS_VRP

As part of the seismic activity in Mayotte, on February 26th, a magnitude 4.8 earthquake (USGS) was recorded.

A mission of the Physical Institute of the Globe of Paris (IPGP), named "Tellus Mayotte", is present on zone from 22 to 28 February 2019 to install seismometers. When recovering the 6 seismometers in 6 months, we should make a big leap in the understanding of the phenomenon that shook Mayotte for nearly 10 months. An island that continues to move, and to sink.

The Journal de Mayotte delivers an interview with the Director of the BRGM:

"It will be remembered that the hypothesis of a magmatic fluid had succeeded to that of a friction of tectonic plates, following an atypical wave recorded on November 11, 2018, which had circled the Earth, and the observation of displacement of the island of Mayotte from 6 cm to the east, and its 7 cm depression, a phenomenon that continues, "without accentuating", indicates Frédéric Tronel, Director of the Office of Geological Research and Minières (BRGM), since we are now at "a displacement of 12 to 14 cm to the east, and a collapse of 10 cm" since June, we must integrate the 2 cm of movement "natural, linked to the movements especially the African Rift "."

 

Source: The Journal of Mayotte.

Monitoring of the seismic swarm underway in Mayotte: magnitudes of earthquakes as a function of time (in day, as of 10/05/2018) - Doc. BRGM

Monitoring of the seismic swarm underway in Mayotte: magnitudes of earthquakes as a function of time (in day, as of 10/05/2018) - Doc. BRGM

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