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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
Santiaguito - pyroclastic flow on 11.20.2020 / 07:33 a.m. - Insivumeh OVSAN

Santiaguito - pyroclastic flow on 11.20.2020 / 07:33 a.m. - Insivumeh OVSAN

Explosive episodes occurred this morning November 20 at the Santiaguito dome complex; they were accompanied by a plume of ash at 3,600 meters asl. and descent of small pyroclastic flows from the top of the Caliente dome to its base, in a westerly direction.

Ash falls are reported in the perimeter of the volcano and populations to the southwest and east.

As reported by the Insivumeh on November 17 (link), this type of event is due to the unstable accumulation of lumpy lava and fine pyroclasts on the dome of the Caliente Dome, causing it to detach and channel into a avalanches and pyroclastic flows.

The prohibition of access to the complex of domes of Santiaguito in an area of ​​5 km. Air traffic could be affected within 20 km. according to the wind direction.

 

Source: Insivumeh Ovsan

Pacaya - Sentinel-2 bands image 12,11,5 from 20.11.2020 - Doc. Insivumeh

Pacaya - Sentinel-2 bands image 12,11,5 from 20.11.2020 - Doc. Insivumeh

In Pacaya, due to night and early morning weather conditions, visibility towards the Mackenney Cone and its crater is limited.

The seismic stations of PCG and PCG5 record tremors associated with the rise of magma and constant degassing in a south-southwest direction.

Lava flow in a west-southwest direction, about 1,030 meters long.

 

Sources: Insivumeh & Sentinel-2

Merapi activity between November 13 and 19, according to BPPTKG report

Merapi activity between November 13 and 19, according to BPPTKG report

Merapi activity between November 13 and 19, according to BPPTKG report

On November 14, 2020 at 6:15 a.m. WIB, avalanches were observed upstream of Kali Lamat with a maximum slide distance of 2 km.There is a change in the morphology of the dome, namely the collapse of part of the dome Lava 2018.

The results of the drone data analysis revealed changes in the morphology of the crater wall due to the collapse of the ancient lava

The volume of the lava dome on November 16, 2020 is 200,000 m³.

The seismic intensity is higher than last week.

Merapi deformation followed by EDM showed a shortening rate of 9 cm / day from reflectors RB1 and RB2.

Conclusion:

There is an increase in volcanic activity on Mount Merapi, so the activity status is set in activity level 3 / siaga.

Current potential dangers come in the form of lava avalanches, eruption of volcanic material in the event of an explosive eruption and pyroclastic flows of up to 5 km.

 

Source: BPPTKG

Merapi - seismicity and deformation at 20.11.2020 - Doc.BPPTKG

Merapi - seismicity and deformation at 20.11.2020 - Doc.BPPTKG

 Merapi this morning - 21.11.2020 / 05h47 - Doc. BPBD Sleman

Merapi this morning - 21.11.2020 / 05h47 - Doc. BPBD Sleman

The typical activity of the Reventador has been characterized in recent months by the generation of gas and ash plumes of varying height on the one hand, and on the other hand by a lava flow on the northeast flank. IGEPN shares a thermal image illustrating this activity.

Reventador - typical activity : gas & ash emission + falling blocks and lava flow - thermal photo / IGEPN

Reventador - typical activity : gas & ash emission + falling blocks and lava flow - thermal photo / IGEPN

From November 19 to 20 at 11 a.m., the seismicity was characterized by :

- 67 earthquakes Long period

- 80 earthquakes

- 17 episodes of emission tremor

- 4 episodes of harmonic tremor

Several gas and ash emissions were observed which reached 800 and 1,200 meters above the level of the crater, the direction of these emissions was towards the southwest. The Washington VAAC recorded 5 ash emission alerts seen in satellites circling heights 700 meters above crater level in a westerly and southwest direction.

FIRMS recorded 4 thermal alerts in Reventador in the last 24 hours

In the afternoon of yesterday and today, for several moments the volcano was clear allowing to observe the described emissions and at night between the clouds, an incandescence was observed in the crater, accompanied by the rolling of blocks on the sides of the volcano. The lava flow is still active (~ 450m) to the northeast and without noticeable changes.

Alert level: orange

Source: IGEPN

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