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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

On February 28, 2019, the Cité du Volcan and the Volcanological Observatory of Piton de la Fournaise organized a press conference to make a point of situation after 10 days of eruption. This conference, open to the public, took place in the Auditorium of the Cité du Volcan.

Piton de la Fournaise - slow progress of the lava flow - 22.02.2019 / 16h30 UT - 26.02.2019 / 16h00 UT - 01.03.2019 / 15h12 UTC - Cascades Webcam - OVPF
Piton de la Fournaise - slow progress of the lava flow - 22.02.2019 / 16h30 UT - 26.02.2019 / 16h00 UT - 01.03.2019 / 15h12 UTC - Cascades Webcam - OVPF
Piton de la Fournaise - slow progress of the lava flow - 22.02.2019 / 16h30 UT - 26.02.2019 / 16h00 UT - 01.03.2019 / 15h12 UTC - Cascades Webcam - OVPF

Piton de la Fournaise - slow progress of the lava flow - 22.02.2019 / 16h30 UT - 26.02.2019 / 16h00 UT - 01.03.2019 / 15h12 UTC - Cascades Webcam - OVPF

After viewing the video, I retain some highlights:

We have 3 seismic crisis for two eruptive phases, of the same eruption.

- The first seismic crisis of February 16th aborted, but marked a magmatic intrusion.

- The second seismic crisis of February 18, following a resumption of seismicity 4 to 5 days before the crisis of 16, resulted in the opening of three active cracks on the outer edge of the Dolomieu, and a short eruption, between 10h30 and 22h local ... with following persistence of a seismic activity.

- The third seismic crisis led to the current eruptive phase.

On February 19th the volcanic tremor is perceived by the OVPF at 17:10; at 17:50, a gas plume is observed by a team present at Piton Bert, and the lava is reported on the surface at 19:12 ...

20.02.2019 - cam.therm. OVPF / NV

an atypical delay of two hours, which suggests a lack of internal pressure, and the belonging of this episode to the same eruption, on a lower crack, the fourth crack, therefore.

The poured stream is divided into 2 branches, the most active of which is at the beginning that of the south.

From February 27, we observe the formation of lava tunnel, and a gradual closure of the cone established on the crack. The spreading and thickening of the casting is progressively progressing, and its progress is very slow (300 m in 5 days), and now only concerns the north casting arm.

Radar interferometry images show a deformation of +/- 20 cm; the volume of lava emitted is estimated at 27.02 at about 5 million cubic meters.

 

As for the evolution, one notices a residual top seismicity, as well as a high concentration of the soil in CO2, and no sign of deflation. These last two parameters are linked to a continuous arrival of magma from the depths. Impossible to say more about the subsequent eruption, and the question of whether lava will reach the lava road or not: In June 2001, it took 25 days for the lava to reach the sea, and in November 2002, 14 days.

 

Source: Aline Peltier / OVPF press conference of 28,02,2019 - link

Popocatépetl - explosion of 01.03.2019 / 3h35 -3h36 - webcambyMexico / Cenapred
Popocatépetl - explosion of 01.03.2019 / 3h35 -3h36 - webcambyMexico / Cenapred

Popocatépetl - explosion of 01.03.2019 / 3h35 -3h36 - webcambyMexico / Cenapred

At Popocatépetl, Cenapred observed 116 exhalations and six explosions, including three on 28 February, and three on 1 March at 3:34, 4:51 and 7:13 am. One hundred and fifty-seven minutes of harmonic tremor were recorded.

The 3:34 explosion expelled incandescent fragments on the flanks over 2km, associated with the destruction of the dome. An overflight on February 28 had found that the # 82 dome still had a diameter of 200 meters.

 

Source: Cenapred.

Popocatépetl - explosion of the 01.03.2019 / 7:15 - webcamsbyMexico / Cenapred

Popocatépetl - explosion of the 01.03.2019 / 7:15 - webcamsbyMexico / Cenapred

Popocatépetl - the dome 82 during the flight of 28.02.2019 - photo Cenapred

Popocatépetl - the dome 82 during the flight of 28.02.2019 - photo Cenapred

The VAAC Darwin issued this 1st March a Red VONA for Manam, Papua New Guinea.

On the satellite images (Himawari 8 and Sentinel 2), a hot spot remains visible and vapor emissions observed; ashes are not identifiable by satellites.

Sources : VAAC Darwin (VA ADVISORY - DTG: 20190301/0550Z
VAAC: DARWIN VOLCANO: MANAM 251020 - PSN: S0405 E14502
) & Sentinel 2

Manam - 01.03.2019 - image Sentinel 2 SWIR - one click to enlarge

Manam - 01.03.2019 - image Sentinel 2 SWIR - one click to enlarge

Manam- Thermal anomalies at 01.03.2019 / 3:55 - Doc. Mirova_MODIS_Latest10NTI

Manam- Thermal anomalies at 01.03.2019 / 3:55 - Doc. Mirova_MODIS_Latest10NTI

Press release issued by the Department of Meteorology and Geohazards of Vanuatu February 28, 2019 on the eruption of Ambrym volcano, December 2018. Some excerpts:

"In mid-December 2018. the eruption of the caldera summit of the moderate scale occurred at the Ambrym volcano.The observations and data analysis by scientists from the geohazards division of the Department of Meteorology and Vanuatu Geo-Hazard (VMGD) suggests that this eruption is now over, however, longer-term aspects of volcanic risk may have changed as a result of this eruption.

Observations and data show that the December 2018 eruption affected three areas on the volcano: the Benbow and Marum summit craters, the summit caldera, and the eastern rift zone to the coast. "
 

Ambrym Volcano Transverse Section: Magma Feeds Benbow and Marum Lava Lakes, Rift Top Eruption and Lava Flow - Doc.VMGD

Ambrym Volcano Transverse Section: Magma Feeds Benbow and Marum Lava Lakes, Rift Top Eruption and Lava Flow - Doc.VMGD

Ambrym - image Sentinel 2 bands 12,11,4 from 15.012.2019 - one click to enlarge

Ambrym - image Sentinel 2 bands 12,11,4 from 15.012.2019 - one click to enlarge

"The eruption began very quickly on December 15 and the Vanuatu volcanic alert level was changed from level 2 to level 3 by the VMGD.

Ambrym - fountains of lava on the crack - photo J.Tasso


Volcanic activities included the drainage of lava lakes, explosive ash eruptions from the Benbow and Marum craters, a short but very dramatic lava eruption on the caldera floor and lava flows.

The magma, being drained from the summit area to the eastern Rift area, experienced large ground cracks, earthquakes and uplift of the coastal zone, and ash falls over North of the island.

The activity in Ambrym subsequently declined and the possibility of a large eruption affecting the entire island is now less likely. This was confirmed from observations and field evaluation conducted from February 3 to 9, 2019, allow in return to alert level 2. The magma intrusion in the rift zone is beginning from the top zone, has now preloaded this area of ​​the volcano and the potential volcanic hazards have changed ... if another intrusion occurs in the Eastern Rift, it is perhaps more easy for the magma to reach the surface, as in the 1913 eruption on the western rift. "

 

Source: VMGD / 01.03.2019

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