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
 Bulusan - photo archives GVP 17.10. 2016. - White steam plumes can be seen rising from other vents. Photo by Drew Zuñiga and provided by 2D Albay, as posted in The Philippine Star

Bulusan - photo archives GVP 17.10. 2016. - White steam plumes can be seen rising from other vents. Photo by Drew Zuñiga and provided by 2D Albay, as posted in The Philippine Star

An increase in the activity of the Bulusan volcano is reported by the Phivolcs.

A total of 124 volcanic earthquakes have been recorded from May 8, 2021 to May 10 by the Bulusan Volcano Network or BVN.

Over the past 24 hours, 166 volcanic earthquakes have rocked the volcano.

The electronic tilt recorded a steady inflation of the upper slopes of the building which began on March 6, 2021. Ground deformation data from continuous GPS measurements indicate slight short-term inflation since February 2021.

Only very weak to weak emission of white vapor laden plumes could be observed currently at the southeast vents.

 

The increased seismic activity and short-term soil deformation is likely caused by shallow hydrothermal processes beneath the building.
The alert level has been raised to 1 on the Bulusan volcano, with a Permanent danger zone (PDZ) of 4 km in radius, and vigilance in the extended danger zone (EDZ) of 2 km in the south-eastern sector which must be exercised because of the increased possibilities of sudden and dangerous phreatic eruptions.

Its last eruption dates back to June 5, 2017 (GVP)


Source: Phivolcs 11.05.2021 19h

Geldingadalur vent # 5 - 11.05.2021 / 05h00 - NB: lava flow in 2 directions - webcam_langihryggur N

Geldingadalur vent # 5 - 11.05.2021 / 05h00 - NB: lava flow in 2 directions - webcam_langihryggur N

More than 50 days have passed since the start of the eruption in Geldingadalur; they can be roughly divided into three.

- The first period lasted about two weeks and was characterized by a fairly regular but slightly decreasing lava flow. The flow increased from 7-8 m³ / s to 4-5 m³ / s in the second week.

- The second period, which also lasted two weeks, was characterized by the opening of new eruptions north of the original craters. The lava flow was quite variable, of the order of 5 to 8 m³ / s.

- In the third period, the last three weeks, one crater dominated and almost all of the lava came out of it. The lava flow increased somewhat during this time. The increase was significant last week and now the rash is much larger than it has been so far.

As of May 10, emissions are 10 to 11 thousand tons / day of CO2, 4000-5000 tons / day of SO2 and about 10 tons / day of hydrogen fluoride (anhydrous hydrofluoric acid)

Fagradalsfjall eruption - surface, volume, discharge, geochemistry, and gas emissions parameters as of May 10, 2021 - Jarðvísindastofnun Háskólans

Fagradalsfjall eruption - surface, volume, discharge, geochemistry, and gas emissions parameters as of May 10, 2021 - Jarðvísindastofnun Háskólans

The latest lava and lava flow size data are based on flights between 12 p.m. and 1 p.m. on May 10, 2021

 There was a significant increase in the lava flow at Fagradalsfjall last week. The average flow over the period is 13 m³ / s, which is much more than the almost 8 m³ / s measured at the beginning of May. (see 3rd parameter insert, above)

Sources: Jarðvísindastofnun Háskólans

The RSAM for the night of May 10, 2021 from the Reykjanes Peninsula stations. The rhythmic behavior reflects the lava fountain (up to 300 m above the ground!) Which occurs at the rate of approximately 8 x / hour. The rash is still in progress.

Source: Kristín Jónsdóttir / IMO / Twitter

Fagradalsfjall - RSAM of 10.05.2021 - Doc. Kristín Jónsdóttir / IMO / Twitter

Fagradalsfjall - RSAM of 10.05.2021 - Doc. Kristín Jónsdóttir / IMO / Twitter

Reykjanes Peninsula - the eruptive site and the lava field as of 11.05.2021 - image Sentinel-2 L1C bands 12,11,4 - one click to enlarge
Reykjanes Peninsula - the eruptive site and the lava field as of 11.05.2021 - image Sentinel-2 L1C bands 12,11,4 - one click to enlarge

Reykjanes Peninsula - the eruptive site and the lava field as of 11.05.2021 - image Sentinel-2 L1C bands 12,11,4 - one click to enlarge

The open channel was relatively narrow and long (reaching a depth of about 17 km) and carrying capacity was limited.

An increase over time indicates that the channel is widening, probably due to erosion of its walls. It is not seen that the pressure in the source has decreased to some extent and therefore the flow rate increases over time as the channel expands.

 

Sources: Jarðvísindastofnun Háskólans / Magnús Tumi Guðmundsson, Sæmundur Ari Halldórsson and Joaquin M. Belart

Piton de La Fournaise - the 2 active cones - photo OVPF 11.05.2021

Piton de La Fournaise - the 2 active cones - photo OVPF 11.05.2021

Piton de La Fournaise - hot spots within the 2 active cones and incandescence of the flow at the level of the Grandes slopes - image Sentinel-2 L1C bands 12,11,4 du 11.05.2021 - one click to enlarge
Piton de La Fournaise - hot spots within the 2 active cones and incandescence of the flow at the level of the Grandes slopes - image Sentinel-2 L1C bands 12,11,4 du 11.05.2021 - one click to enlarge

Piton de La Fournaise - hot spots within the 2 active cones and incandescence of the flow at the level of the Grandes slopes - image Sentinel-2 L1C bands 12,11,4 du 11.05.2021 - one click to enlarge

The slow decrease in the tremor initiated at Piton de la Fournaise since May 2 continues. However, its amplitude remains significant, still reaching 30% of the maximum amplitude observed during this eruption on April 13.

The two cones are still active, with degassing and projections of lava present at the downstream cone.

 

The OVPF reports a significant gas plume on May 12, covering the whole of the Enclosure. The most extreme caution is recommended.

 

Source: OVPF

Piton de La Fournaise - the enclosure under the gas plume - photo OVPF 12.05.2021 / 07h59

Piton de La Fournaise - the enclosure under the gas plume - photo OVPF 12.05.2021 / 07h59

Piton de La Fournaise - the eruptive site on 05.12.2021 / 08:17 - pano webcam / OVPF

Piton de La Fournaise - the eruptive site on 05.12.2021 / 08:17 - pano webcam / OVPF

Commenter cet article

Articles récents

Hébergé par Overblog