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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
Santa Maria complex- image Sentinel-2 bands 12, 11, 8A from 03.12.2021 / 4:36 p.m. - via Mounts project

Santa Maria complex- image Sentinel-2 bands 12, 11, 8A from 03.12.2021 / 4:36 p.m. - via Mounts project

The Santiaguito volcano maintains a white degassing at the level of the dome; it also generated weak and moderate explosions accompanied by ash columns at an altitude of 3000 meters, dispersing to the northwest and west at a distance of 10 kilometers. Ashes fell on the villages of San Marcos Palajunoj, Loma Linda and others in this region.

The seismic stations of STG3 and STG8, record moderate and strong explosions and avalanches in the west and southwest, sometimes forming ash curtains in their movement.

The Insivumeh reminds that the Santiaguito is in a period of extrusion of lava in blocks in the crater, this can cause moderate to strong pyroclastic flows, so you should not stay near or in the channels of the rivers near the slopes of the volcano. .

 

Source: Insivumeh / OVSAN

Santiaguito - Image Sentinel-2 bands 12,11,5 du 03.12.2021 - Doc. Insivumeh

Santiaguito - Image Sentinel-2 bands 12,11,5 du 03.12.2021 - Doc. Insivumeh

On December 3 in La Palma, a new flow was located south of the secondary cone ... a cone that currently remains the main source of pyroclasts and ash.
The Cumbre Vieja volcano has resumed activity in its main cone, with the expulsion of a dense column of ash and gas after several days of virtually no activity.

At sunset, the volcano emitted glowing pyroclastic material in its southeastern part, and its activity is barely visible from Tajuya.

La Palma / Cumbre Vieja northeast flank - little activity around 5 p.m. on 03.12.2021 - Photo InVolcan FB

La Palma / Cumbre Vieja northeast flank - little activity around 5 p.m. on 03.12.2021 - Photo InVolcan FB

La Palma / Cumbre Vieja - 03.12.2021 / 19h00 - photo InVolcan FB

La Palma / Cumbre Vieja - 03.12.2021 / 19h00 - photo InVolcan FB

Yesterday's trend appears to continue this December 4, with less vigorous activity on the surface and fewer earthquakes today (just 24 earthquakes of magnitude 3.0 or greater, the largest event of 4.2 in 24 hours), but at depth, a new surge of magma could be brewing. This translates into an increase in inflation.
The volcanic tremor remains at strongly fluctuating moderate levels.

 

The PEVOLCA indicates that the eruptive activity continues to concentrate mainly on the northeast flank, where the accumulation of pyroclasts has led to the formation of a cone of pyroclasts with strombolian and effusive activity which emits lava flows. The main contribution of lava passes through the central area and the area affected by the eruption amounts to approximately 1,144 hectares and 70 kilometers of roads and other roads. On the other hand, the air quality remains at good or regular levels in all the resorts of the island with the exception of Los Llanos de Aridane where it is unfavorable. The weather forecast for today does not exclude the impact on La Palma of the intrusion of Saharan dust, increasing the small particles of dust. La Palma airport is still operational.

 

Sources: IGN, InVolcan, DSN, Pevolca

La Palma - seismicity decreasing as of 12/04/2021 - 7:02 am - Doc. IGN

La Palma - seismicity decreasing as of 12/04/2021 - 7:02 am - Doc. IGN

Between November 26 and December 2, the BPPTKG reports an increasing seismicity in Merapi compared to the previous period.

Incandescent boulder falls have been observed 170 times to the southwest with a maximum slip distance of 2,000 m.

On December 1, 2021, there were 2 pyroclastic avalanche flows to the southwest with a maximum glide distance estimated at 3,000 m.

Light ash rains were reported in the east-southeast area of ​​Mount Merapi namely Mriyan, Sangup Tamansari Boyolali and Gedongijo Klaten.

 

It is observed that there is a decrease in the height of the southwest dome of about 2 m, while the morphology of the central lava dome is not observed to have a significant change. The volume of the southwest lava dome is 1,615,000 m³ and the central dome is 2,948,000 m³.

The deformation of Mount Merapi, which was monitored using EDM this week, showed a distance shortening rate of 0.7 cm / day.

Merapi - activity from 26.11. to 02.12.2021 - Doc. BPPTKG

Merapi - activity from 26.11. to 02.12.2021 - Doc. BPPTKG

Merapi - evolution of the summit area on 02.12.2021 - Doc. BPPTKG

Merapi - evolution of the summit area on 02.12.2021 - Doc. BPPTKG

MErapi - sismicity 26.11.2021 * 02.12.2021 - Doc. BPPTKG

MErapi - sismicity 26.11.2021 * 02.12.2021 - Doc. BPPTKG

The volcanic activity of Mount Merapi is still quite high in the form of effusive eruption activity. The state of the activity remains in Siaga

The current potential danger consists of lava avalanches and hot clouds in the southeast-southwest 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. During this time, the ejection of volcanic material in the event of an explosive eruption can reach a radius of 3 km from the summit.

 

Source: BPPTKG

Grimstvötn - discharge on 04.12.2021 / 07:59 - Doc. Iceland Univ. & IMO

Grimstvötn - discharge on 04.12.2021 / 07:59 - Doc. Iceland Univ. & IMO

The Grímsvötn ice cap started to subside and water started draining from the lake 10 days ago. IMO GPS instruments show that the ice cap has now sunk more than 27 meters.

This December 3, between 10:15 am and 12:20 pm, the hydrologists of the IMO measured a flow of approximately 1600 m³ / s in Gígjukvísl. Electrical conductivity, which is an indicator of the amount of geothermal meltwater in the river, has also increased over the past two days and now exceeded 464 µS / cm. Higher than normal gas concentrations have been measured at the edge of the glacier, but they are currently within health and safety levels.

The most recent measurements are consistent with the flood forecasting model, and it is highly likely that the floods will peak on Sunday. IMO is monitoring the area very carefully to see if there are any indications of increased seismicity or gas that could indicate an impending eruption.

 

Source: IMO

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