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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
 Sabancaya - intracratric dome observed during drone overflights on 11-12.12.2019 - Doc IG Peru

Sabancaya - intracratric dome observed during drone overflights on 11-12.12.2019 - Doc IG Peru

During the past week, the eruptive activity of the Sabancaya volcano in Peru has not shown any major variations. Each day, on average, 23 explosions generated columns of gas and ash up to 3.3 km high at the top of the volcano. The ashes were dispersed towards the north-west, west and south-west sectors of Sabancaya, that is to say towards the sectors of Cabanaconde, Huambo, LLuta and Huanca.

The images captured during the overflights of December 11 and 12 clearly show the morphology of the crater of the volcano and the location of a dome, which grew inside the crater, but without going beyond the edges. IGP researchers processed all the collected material to determine possible danger scenarios, including the possibility of the lava dome collapsing and the generation of pyroclastic flows.

 

Source: IGP / CENVUL

Rincon de La Vieja - 18.12.2019 - one of the areas affected by intense erosion due to morphological changes in the southern flank of the active crater. - RSN / Photo Juan Carlos Lopez - ICE

Rincon de La Vieja - 18.12.2019 - one of the areas affected by intense erosion due to morphological changes in the southern flank of the active crater. - RSN / Photo Juan Carlos Lopez - ICE

Seismic activity continued during the past week at Rincon de La Vieja, with the appearance of long-term earthquakes (just over two dozen) and a volcano-tectonic earthquake, recorded at the most close to the volcano. Sporadic signs of spasmodic tremors, and on some harmonic occasions, are observed.

It is recommended to stay away from drainages near the volcano in the event of an eruption, due to the possibility of generation of primary lahars. As well as in case of rain, since secondary lahars could be generated by ash and materials accumulated in the upper parts of the volcano.

 

Source: RSN Costa Rica

 Whakaari -19.12.2019 - thermal image of gas fumes. - GeoNet

Whakaari -19.12.2019 - thermal image of gas fumes. - GeoNet

At Whakaari / White Island, very hot gases and steam are evacuated through active vents at the back of the crater basin. The volcanic tremor continues at a low level. New eruptions are unlikely in the coming days. The volcanic alert level remains at level 2.

On an afternoon of December 19, an observation flight confirmed the opening of steam and gas vents, one of which discharges at more than 650 ° C. These data confirm our previous interpretations according to which the shallow magma is located under the ventilation area. No magma or lava was seen.
The data processed during yesterday's gas measurement flight confirm that high levels (~ 15 kg / s) of sulfur dioxide continue to be released. The values ​​are slightly lower than those (~ 20 kg / s) measured on December 12.
Yesterday's aerial observations clearly showed that a moderately small part of the southwest slope of the 1914 landslide (inside the crater rim and opposite the old observation area) has collapsed in the crater lake area, including the area of ​​active vents, leaving a scar 12 meters high. This collapse occurred during or immediately after the eruption, but the area is known as a previously unstable area and will continue to be monitored.

Source : GeoNet

Nishinoshima - 15.12.2019 - activity at the top and on the sides of the cone; and lava flows - photo Japan Coast Guards

Nishinoshima - 15.12.2019 - activity at the top and on the sides of the cone; and lava flows - photo Japan Coast Guards

The activity continues on Nishinoshima:

- Thermal anomalies are noted by Mirova, considered as high;

- SAR interferometry performed by DAICHI-2 between November 17 and December 15, 2019 and december 6- 20,2019 allows  to observe the topographic changes on the northwest coast of the island, due to lava deposits.

 

Sources: GSI Survey Institute Yuki Hatanaka - Japan coast guards - Mirova

Nishinoshima - SAR interferometry- DAICHI-2 - on the left, between 17.11.2019 and 15.12.2019; right, between 06 and 20.12.2019 - GSI analysis of ALOS-2 raw data from JAXA - one click to enlargeNishinoshima - SAR interferometry- DAICHI-2 - on the left, between 17.11.2019 and 15.12.2019; right, between 06 and 20.12.2019 - GSI analysis of ALOS-2 raw data from JAXA - one click to enlarge

Nishinoshima - SAR interferometry- DAICHI-2 - on the left, between 17.11.2019 and 15.12.2019; right, between 06 and 20.12.2019 - GSI analysis of ALOS-2 raw data from JAXA - one click to enlarge

Nishinoshima - high thermal anomalies on 20.12.2019 / 03h25 - Doc. Mirova_MODIS_Latest10NTI

Nishinoshima - high thermal anomalies on 20.12.2019 / 03h25 - Doc. Mirova_MODIS_Latest10NTI

As a bonus, a 3D infrared model of Reventador, in Ecuador.

Produced by IGEPN on the basis of thermal images from November 14, 2019, with the participation of the airline Alas del Socorro, it will identify and quantify the morphological changes in the volcano.

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