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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
Nevados de Chillan - infographic Sernageomin / 09.2021 explaining the presence of 2 lava domes

Nevados de Chillan - infographic Sernageomin / 09.2021 explaining the presence of 2 lava domes

Nevados de Chillan - 3rd dome identified on a SkySat satellite image - Doc. Sernageomin

Nevados de Chillan - 3rd dome identified on a SkySat satellite image - Doc. Sernageomin

From the photo-interpretation of a very high resolution SkySat-type image dated September 15, 2021, the growth of an effusive body attributable to a dome-shaped morphology inside the Nicanor crater of the Nevados de Chillan complex is identified.

Ellipsoidal in shape, it has a major axis of 40 m and a minor axis of 27 m. It has an elongated shape in a northwest-southeast direction.

From the analysis of Sentinel-2 L2A satellite images of the same date, it is confirmed that it has abnormal thermal radiation.

In terms of surface activity, the appearance of this new morphology is preceded by a considerable decrease in the rate of extrusion of L5 and L6, disappearance of the thermal anomalies which explain a decrease in the temperature of these lava flows, as well as the disappearance of episodes of incandescence
nocturnal during most of the first half of September.

The RSAM of the continuous seismic signal, calculated every 6 hours, shows a gradual rise since yesterday 14
September, coinciding with a greater record of volcanic seismic signals, in particular LP and tremor.

 

Source : Sernageomin & Mirova

Nevados de Chillan - thermal anomaly in the crater - image Sentinel -2 bands 12,11,8A 09.15.2021 / 2:37 p.m. via Mounts project

Nevados de Chillan - thermal anomaly in the crater - image Sentinel -2 bands 12,11,8A 09.15.2021 / 2:37 p.m. via Mounts project

Nevados de Chillan - thermal anomalies at 09.17.2021 / 03.40 a.m. - Doc. Mirova_MODIS_Latest10NTI

Nevados de Chillan - thermal anomalies at 09.17.2021 / 03.40 a.m. - Doc. Mirova_MODIS_Latest10NTI

The lava flow during the eruption in Geldingadalur increased on September 16, 2021. A first appearance of the incandescence at the re-entry of the flows in Nátthaga is visible on the webcam around 7:50 pm. Around midnight, lava flows again, very fluid, over the foothills of the Nátthaga Valley, similar to that of September 15.


The turning point of the Fagradalsfjall eruption today is that the eruption has become the longest eruption in Iceland in the 21st century, with 181 days since the eruption started on March 19. As a result, the rash lasted longer than the Holuhraun rash, which lasted 180 days. The eruption began there on August 31, 2014 and ended on February 27, 2015.


Nothing indicates an end of eruption.

 

Sources: RUV, mbls, Dr. E.Ilyinskaya

NinaNX video - https://youtu.be/FHQAxqJc7m0

Fagradalsfjall - tremor at 17.09.2021 - Doc. Hraun.vedur.is

Fagradalsfjall - tremor at 17.09.2021 - Doc. Hraun.vedur.is

The white plume of Bromo (Tengger caldera on Java) was observed with fluctuating intensity about 50-500 meters from the summit on September 15, 2021.

PVMBG signals a continuous tremor episode, with an amplitude of 0.5-1 mm, dominant at 1 mm.

The activity level is at 2 / waspada.

Communities around Mount Bromo and visitors / tourists / climbers are recommended not to enter the area within 1 km of the active crater of Mount Bromo.
Communities around Mount Bromo, traders, tourists, mountaineers, and Mount Bromo tour operators should be aware of the occurrence of sudden phreatic eruptions and without being preceded by obvious volcanic symptoms.

 

Sources: PVMBG, Magma Indonesia, Oystein Lund Andersen (photo of 16,09,2021 / https://twitter.com/oysteinvolcano/status/1438508528310702082/photo/2)

Bromo - gas and steam plume 09.15.2021 / 09:19 AM WIB - PVMBG-Magma Indonesia webcam

Bromo - gas and steam plume 09.15.2021 / 09:19 AM WIB - PVMBG-Magma Indonesia webcam

In La Palma, the seismic activity continues to migrate slightly to the northwest, at depths of around 8 km, recording, in addition, 50 shallow earthquakes between 1-5 km. The maximum cumulative deformation reaches about 10 cm.

 

The seismic activity started at 3:18 am (UTC) on the 11th. At 9:30 am (UTC) today, 4,530 earthquakes were detected in the southern area of ​​the island of La Palma, of which they located a total of 1,023. The activity continues to migrate slightly in a north-westerly direction. Since 00:11 (UTC) on the 15th, 50 earthquakes have been located at depths between 1 and 5 km. The energy accumulated so far is 2.8 × 1011 Joules.

The maximum cumulative vertical deformation is of the order of 10 cm in the zone close to seismicity and its distribution is still compatible with a center of pressure in this zone. These movements were observed both with the island's GNSS network and with InSAR data (Sentinel-1).

According to InVolcan / Instituto Volcanologico de Canarias, 11 million cubic meters of magma have already been injected inside Cumbre Vieja.

 

Sources: IGNes - 16,09,2021 / 13h UTC & INVOLCAN

La Palma - seismic swarm on 16.09.2021 - Doc. IGNes

La Palma - seismic swarm on 16.09.2021 - Doc. IGNes

La Palma - horizontal and vertical movement in some of the GNSS stations - Doc. InVOLCAN 09.16.2021

La Palma - horizontal and vertical movement in some of the GNSS stations - Doc. InVOLCAN 09.16.2021

INVOLCAN continues to work in the field. Colleagues Alba and Bev take gas samples to be able to estimate the level of carbon dioxide emitted by the volcanic system of Cumbre Vieja / photo Twitter 16.09.2021

INVOLCAN continues to work in the field. Colleagues Alba and Bev take gas samples to be able to estimate the level of carbon dioxide emitted by the volcanic system of Cumbre Vieja / photo Twitter 16.09.2021

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