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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
 Pavlof - ash emission on 05.08.2021 - Code Orange - Doc. AVO

 Pavlof - ash emission on 05.08.2021 - Code Orange - Doc. AVO

Unrest continues at Pavlof volcano and minor ash emissions just above the top of the volcano were observed on August 5, 2021. Seismic tremors and small explosions were detected by local seismic and infrasound instruments. The ash emissions observed were of limited extent and probably only produced local fallout on the southeast flank of the volcano.

The level of restlessness at Pavlof can change rapidly and progression to rash activity may occur with little or no warning.

Ash emissions indicate an active eruption in progress, so the Alaska Volcano Observatory is raising the Aviation Color Code and Alert Level to ORANGE / WATCH.

 

Note that in the area under the responsibility of the AVO, three volcanoes are on Watch / orange alert : the Great Sitkin, the Pavlof and the Semisopochnoi.

 

Source: AVO / Alaska Volcano Observatory

Fagradslasfjall - activity at the cone and lava flows on 08.062021 / 01h52 - webcam_langihryggur / RUV

Fagradslasfjall - activity at the cone and lava flows on 08.062021 / 01h52 - webcam_langihryggur / RUV

Fagradalsfjall - activity continued all day - webcam langihryggur NV / Almannavarnir 08.06.2021 / 22h50

Fagradalsfjall - activity continued all day - webcam langihryggur NV / Almannavarnir 08.06.2021 / 22h50

In Fagradalsfjall, the activity was maintained all day yesterday, with feeding of the lava flows in several arms; ke trémor testifies to a new stability.

 

Sources: webcams & Hraun.vedur

Fagradalsfjall - tremor at 07.08.2021 - Doc. Hraun.vedur

Fagradalsfjall - tremor at 07.08.2021 - Doc. Hraun.vedur

The volcanic activity of Merapi remains quite high, during the week of July 30 and August 5, 2021, in the form of effusive eruption activity.

The PVMBG provides information over the period of 7 pyroclastic avalanche flows in the southwest with a maximum glide distance of 2,000 m. Boulder collapses were observed 84 times to the southwest with a maximum slide distance of 2,000 m.

Based on the morphological analysis of the Deles5, Tunggularum, Ngepos and Babadan2 camera stations, the southwest lava dome increased by about 3 m. with a volume of 1,895,000 m³. The volume of the central dome is relatively fixed.

The deformation of Mount Merapi, which was monitored using EDM this week, showed a distance shortening rate of 12 cm / day.

The activity level remains at level 3 / Siaga. The current potential danger consists of lava avalanches and pyroclastic flows in the south-east-south-west sector for a maximum of 3 km to the Woro River, and 5 km to the Gendol, Kuning, Boyong rivers, Bedog, Krasak, Bebeng and Putih; and the ejection of volcanic material in the event of an explosive eruption can reach a radius of 3 km from the summit.

Aviation code on 06.08.2021: Orange (VAAC Darwin)

 

Sources: PVMBG, Magma Indonesia, BPPTKG, VAAC Darwin

Merapi - weekly report on summit morphology - Doc. BPPTKG 05.08.2021 - one click to enlarge

Merapi - weekly report on summit morphology - Doc. BPPTKG 05.08.2021 - one click to enlarge

Merapi - seismicity at 05.08.2021 - Doc. PVMBG Magma Indonesia

Merapi - seismicity at 05.08.2021 - Doc. PVMBG Magma Indonesia

According to a news source, residents of Savo in the Solomon Islands reported an increase in seismicity to authorities on July 28.

Two days later, a team from the Geological Survey Division (GSD) and the National Disaster Management Office (NDMO) investigated the volcano. They saw steam and gas emissions rising from an area of ​​the crater, possibly indicating an active crack, and questioned residents. The GSD briefed the National Disaster Operations Committee and other authorities on July 31, confirming the increase in seismicity and prompting a preparedness response.

Response actions included the continued surveillance of the island, the deployment of technical teams and the issuance of safety messages on the volcanoes to inform residents of the island as well as the surrounding areas.

Source: SBM Online / GVP

Savo island - Sentinel-2 bands image 12,11,4 from 06.08.2021 - one click to enlarge the satellite images
Savo island - Sentinel-2 bands image 12,11,4 from 06.08.2021 - one click to enlarge the satellite images

Savo island - Sentinel-2 bands image 12,11,4 from 06.08.2021 - one click to enlarge the satellite images

The 6 x 7 km island of Savo consists of a wooded, andesitic to dacitic stratovolcano, with a shallow, elliptical, 1 x 1.5 km wide summit crater. Lava domes of historic age are located on the crater floor and its NE rim, and older domes are found on the flanks of the volcano.

Pyroclastic flows and mudslides descended the valleys from the summit crater to form fans of debris along the coast. The thermal zones located in the summit crater, the southern flanks to the southeastern flanks and offshore include areas of smoking soil, fumaroles, small geysers and hot springs.

The last eruption of VEI 3 dates from 1835 to 1847, according to the GVP

 

Source: Global Volcanism Program

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