Overblog
Editer l'article Suivre ce blog Administration + Créer mon blog

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
Poas - first images from the webcam on 06.04.2022 / 05:22 - Ovsicori - one click to enlarge

Poas - first images from the webcam on 06.04.2022 / 05:22 - Ovsicori - one click to enlarge

On April 6, 2022 at 2:42 a.m. local time, an eruption was recorded at the Poas volcano, Costa Rica, with an eruptive column that reached 500 meters above the crater (3208 meters above sea level) .
Duration of the activity: 3 minutes.

 

The explosive event formed a crater approximately 45 m in diameter in the north wall of the crater, which caused material to be expelled towards the Laguna Caliente area. A mound of pyroclastic rocks detached reaching a height of 4 meters above lake level and extending for 150 meters, until it reached the center of Laguna Caliente. Fumaroles remained active at this location.

Poas - situation on 06.04.2022 / 06:38 - We can see the new crater, the landslide to the middle of the acid lake, the floating sulfur and the gray tint of the waters - Ovsicori webcam - one click to enlarge

Poas - situation on 06.04.2022 / 06:38 - We can see the new crater, the landslide to the middle of the acid lake, the floating sulfur and the gray tint of the waters - Ovsicori webcam - one click to enlarge

It is possible that this material is the mixture of a pyroclastic current of density due to the explosion, as well as the landslide that occurred. The affected area is approximately 7,500 m2.
The material ejected, as well as the intensity of the explosion, could correspond to a phreatic type explosion, possibly triggered by the increase in pressure and temperature of the gases coming from the interior of the volcano and which could possibly break a plug of sulphur. This coincides with the appearance of sulfur floating in the Laguna Caliente, as well as a change in the color of the lake, which is grayish.

The fumaroles on the north and east walls remain very active, as well as the underwater fumaroles. Frequent earthquakes of low frequency and low amplitude are recorded. The H2S/SO2 ratio and the SO2 concentration remain stable. Geodetic monitoring shows the stability of the volcanic edifice.

 

Source: Ovsicori

Sangay - an ash cloud is observed over Guayas heading west on 05.04.2022 / 8:50 am Loc. - Goes-16 / IGEPN satellite image

Sangay - an ash cloud is observed over Guayas heading west on 05.04.2022 / 8:50 am Loc. - Goes-16 / IGEPN satellite image

This April 5, 2022, the VAAC in Washington reported 3 ash emission alerts for Sangay / Equateur, ranging from 570 to 1770 meters above crater level in a westerly direction, and thanks to the satellite system GOES-16, it is possible to appreciate the movement of the ash cloud to the west.
The FIRMS system records 35 thermal alerts, while the MIROVA system records 1 very high thermal alert (1242 MW) in the last 24 hours.
No emissions were observed due to low visibility. In the afternoon, the report of ash fall near Palmira (Chimborazo Province) was received by the Network of Volcanic Observers of Ecuador.

 

From 9:15 p.m. TL, the SAGA seismic station recorded a tremor signal probably linked to the eruptive activity of Sangay. The amplitude of the signal is low compared to the most active pulses of the current eruptive period of the volcano. Therefore, there is a low probability of ash fall in areas surrounding the volcano.

Alert level - SNGRE: Yellow / high activity, increasing.

 

Source: IGEPN

Sangay - eruptive plume of 06.04.2022 / 12:20 p.m. - IGEPN webcam

Sangay - eruptive plume of 06.04.2022 / 12:20 p.m. - IGEPN webcam

The IGEPN transmitted a map of the flows from the Wolf volcano, on Isabela Island in the Galapagos, updated to 05.04.2022 based on thermal anomalies.

For this day, there are no reports from the VAAC of Washington, nor anomalies observed by satellite. The FIRMS system records 52 thermal alerts, while the MIROVA system records 2 high thermal alerts (376 and 883 MW) in the last 24 hours.

During this day, 3 VT earthquakes were recorded

 

Source: IGEPN

Galapagos, Isabela island - Wolf volcano - location of thermal alerts updated on 05.04.2022 - Doc. IGEPN - one click to enlarge

Galapagos, Isabela island - Wolf volcano - location of thermal alerts updated on 05.04.2022 - Doc. IGEPN - one click to enlarge

During the period evaluated from 29.03 to 04.04.2022, the levels of seismic activity associated with rock fracturing (VT type) and fluid dynamics (LP type - Long Period and TR - Volcanic Tremor) remained high in recurrence. VT-type seismicity continued to occur mainly 800 m SE of the crater of the Puracé volcano. Other centers can also be found on this site.

Puracé - fumaroles active on 04.04.2022 - Doc. CMS

Puracé - fumaroles active on 04.04.2022 - Doc. CMS

The eruptions of the Los Coconucos volcanic chain, highlight the activity of the Curiquinga volcano; It should be noted that this activity was characterized by the presentation of weak earthquakes
magnitudes and with depths of 2 km on average.
The GNSS (Global Navigation Satellite System) geodetic network and the DInSAR (Differential Interferometry by Synthetic Aperture Radar) processing, used to monitor the deformation of the ground, record two important processes: one associated with an inflationary process of the order of a millimetre, and the other to a co-seismic deformation process following the magnitude 3.3 ML VT event on December 29, 2022 at 12:14 p.m. (local time). These processes continue to be recorded as of this date.

Puracé – VT earthquakes in the Los Coconucos volcanic chain from March 1 to April 4, 2022 – Doc. SGC - one click to enlarge

Puracé – VT earthquakes in the Los Coconucos volcanic chain from March 1 to April 4, 2022 – Doc. SGC - one click to enlarge

An increase in sulfur dioxide and carbon dioxide (SO2, CO2) gas emissions has been detected, both instrumentally and by direct sampling. Similarly, the fumarole located on the northern flank of the Puracé volcano showed changes in its external dynamics (increased pressure of the expelled gas and strong sulfur odors). On the other hand, the emission of SO2 was corroborated by the processing of satellite images, as well as the formation of two cracks about 40 m long, through which an emission of volcanic ash occurred on March 29.

The activity level is currently at 3 (yellow level), which could evolve into higher activity states. The Colombian Geological Service continues to monitor the evolution of the volcanic phenomenon and will report any changes that may occur in due course.

 

Source: SGC

Commenter cet article

Archives

Articles récents

Hébergé par Overblog