Overblog
Editer l'article Suivre ce blog Administration + Créer mon blog

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
The eruptive site of Fagradalsfjall - Icelandair advertisement dated 19.04.2021

The eruptive site of Fagradalsfjall - Icelandair advertisement dated 19.04.2021

In the Reykjanes Peninsula, the eruption of Fagradalsfjall (name by which scientists seem to want to refer to it today) has been going on for a month, without showing signs of weakening.

A summary from the University Institute of Earth Sciences indicates that the average lava flow during the first 30 days is 5.6 m³ / s. Compared to most other eruptions, the flow is relatively stable. Lava measurements now show that there has been some increase over the past 1-2 weeks. The average flow for the first 17 days was 4.5 to 5 m³ / s, but for the last 13 days it is close to 7 m³ / s.

Parameters of the eruption at Fagradalsjall (as the authorities seem to designate it), on April 18, 2021 / 12:10 p.m.: surface and volume occupied by lava - discharge ratio - composition - daily emission rate of SO2, CO2 and water hydrofluoric acid. Univ. From Iceland, IMO & al.

Parameters of the eruption at Fagradalsjall (as the authorities seem to designate it), on April 18, 2021 / 12:10 p.m.: surface and volume occupied by lava - discharge ratio - composition - daily emission rate of SO2, CO2 and water hydrofluoric acid. Univ. From Iceland, IMO & al.

The University Institute of Earth Sciences on eruption lava flow measurements.

The results are the total flow from all craters over a six-day period, April 12-18. The month of April had averaged nearly 8 m³ / s. , slightly increasing from the average eruption flow and confirming that in parallel with the opening of more craters last week, the power of the eruption increased somewhat, the lava area reached 0.9 km² and the total volume now exceeds 14 million cubic meters.

The development of the lava zone is not as "linear" as the development of volume, but this is because at first the lava field increased to thickness inside Geldingadalur rather than to spread.

The eruptive site of Fagradalsfjall - image Sentinel-2 bands 12,11,4 of 19.04.2021 - Doc. Sentinel HUB

The eruptive site of Fagradalsfjall - image Sentinel-2 bands 12,11,4 of 19.04.2021 - Doc. Sentinel HUB

April 18 Peripetia: The northernmost crater in the Reykjanes Peninsula's eruption zone, which opened on April 5, has ceased to erupt, as evidenced by aerial photographs by experts from the Institute of natural history yesterday.

This crater was the highest on the eruptive site; these conditions may explain why the lava flow found it more convenient to exit through other openings.

 

Sources: IMO, Univ Iceland, RUV, mbls, Óróapúls

The eruptive site of Fagradalsfjall / Meradalur - extinction of the northest vent - RUV webcam 04.19.2021

The eruptive site of Fagradalsfjall / Meradalur - extinction of the northest vent - RUV webcam 04.19.2021

Between April 12 and April 18, 2021, Sabancaya's activity remained at moderate levels, with an average of 91 explosions per day, accompanied by plumes of ash and gas up to 2,300 meters above the summit.

Seismicity is characterized by 1,732 earthquakes of volcanic origin, associated with the internal circulation of magmatic fluids. Volcano-tectonic earthquakes, in connection with the fragmentation of rocks, occurred in a north-west and east sector, of magnitude between 1.6 and 3.9.

No deformation anomalies, set aside a slight inflation in the northern sector. Eight thermal anomalies were identified, with a max. of 28 MW, associated with a body of surface lava in the crater.

The volcanic alert remains orange, with an inaccessible area of ​​12 km in radius.

 

Source: I.G. Peru

Sabancaya - Activity between 12 and 18.04.2021 - Doc. I.G. Peru

Sabancaya - Activity between 12 and 18.04.2021 - Doc. I.G. Peru

The seismic activity at La Soufrière in St. Vincent continued the pattern established after the explosive activity of April 18 in the evening.
Small, long-lived and hybrid earthquakes continued to be recorded. No volcano-tectonic earthquakes, rock falls or tremors have been recorded in the past 12 hours.
The continuous GPS network showed a change in horizontal and vertical movement from the initial depressurization seen immediately after the explosive phase of April 9.

 

Its pattern of seismic activity over the past few days is typical of the growth and destruction of lava domes.
Explosions accompanied by falling ash, of a similar or greater magnitude, may occur with little or no warning affecting Saint-Vincent and the neighboring islands.
The volcano is at the Red alert level.

 

Source: UWI-SRC

Soufrière of St. Vincent - 04/18/2021 - photo Thomas Christopher, UWI-SRC / MVO

Soufrière of St. Vincent - 04/18/2021 - photo Thomas Christopher, UWI-SRC / MVO

At Sinabung, a white plume was observed on April 19 between 50 and 700 meters above the summit.

Seismicity remains high; it is characterized by:

- 1 earthquake linked to a pyroclastic flow
- 6 eruption earthquakes
- 99 collapse / avalanche earthquakes
- 4 blast / emission earthquakes
- 6 low frequency earthquakes
- 12 hybrid / multiphase earthquakes
- 10 deep volcanic earthquakes
- 1 local tectonic earthquake and a distant one.

The level of activity remains unchanged, at 3 / siaga, as do the no-go zones.

Sources: PVMBG, Magma Indonesia, Nachelle Homestay.

Sinabung - 04.19.2021 / 10.51am WIB - webcam PVMBG / Magma Indonesia

Sinabung - 04.19.2021 / 10.51am WIB - webcam PVMBG / Magma Indonesia

Sinabung - 04.20.2021 / 06:23 - photo Nachelle Homestay

Sinabung - 04.20.2021 / 06:23 - photo Nachelle Homestay

Commenter cet article

Articles récents

Hébergé par Overblog