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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 - active degassing on 08/28/2020 - photo Conred

Santiaguito - active degassing on 08/28/2020 - photo Conred

The activity of the Caliente dome, part of the Santa Maria-Santiaguito volcanic complex, continues.

The extrusion of fresh volcanic material continues and solidifies, despite a temperature high enough to cause nocturnal incandescence. This lava does not flow down, but piles up at the top of the dome, until it is moved by gravity or explosions, forming avalanches of boulders and ash descending to the base of the dome, mainly on its southwest flank.

The number of explosions, accompanied by plumes of ash is maintained between 2 and 4 per hour; these explosions are interspersed with periods of degassing, forming plumes of vapors rising 500 meters above the dome.

These manifestations testify to a possible increase in the internal activity of the dome, with an increase in extrusions and collapses that can generate greater pyroclastic density currents.

 

Insivumeh maintains the ban on climbing, the exclusion zone of 5 km in radius and recommends that aviation stay outside the 10 km of the domed complex on the west and southwest side, due to the ash plumes that can be issued.

 

Source: Insivumeh & Conred
 

Santiaguito - A: incandescence of the Caliente dome and degassing / photo 08/27/2020 at 9:46 p.m. local - B: explosion and avalanche of incandescent blocks on 08/28/2020 / 3:23 local - Doc. Insivumeh - one click to enlarge

Santiaguito - A: incandescence of the Caliente dome and degassing / photo 08/27/2020 at 9:46 p.m. local - B: explosion and avalanche of incandescent blocks on 08/28/2020 / 3:23 local - Doc. Insivumeh - one click to enlarge

Since the end of April, the seismicity of the Pacaya has shown an increase in episodes of its explosive strombolian activity, which is accompanied by lava flows within the crater and on the medium-high part of the northern sector flanks, and fallout.

In recent weeks, however, there has been a downward trend in the amplitude of RSAM and explosive activity.

Pacaya - 08.28.2020 - RSAM of the past fortnight - Insivumeh Doc

Pacaya - 08.28.2020 - RSAM of the past fortnight - Insivumeh Doc

Currently, the lava effusion feeds two active flows on the northern flank and the northeast flank, respectively 600 and 300 meters in length. These flows degass abundantly, and keep a high temperature, visible on the satellite images in the bands sensitive to IR.

The Insivumeh maintains the ban on climbing the Mackeney Cone, and more specifically access to the northern and northeastern flanks of the Pacaya, due to the activity and its instability.

 

Sources: Insivumeh & Conred

Pacaya - 08.28.2020 - A: incandescence at the top of Pacaua seen by Landsat-8 - B: incandescence, degassing and lava flow at Mackenney - Doc. Insivumeh

Pacaya - 08.28.2020 - A: incandescence at the top of Pacaua seen by Landsat-8 - B: incandescence, degassing and lava flow at Mackenney - Doc. Insivumeh

The Fuego Volcano Observatory reports 5 to 10 Vulcanian explosions, weak and moderate per hour, during the night and early in the morning which expelled plumes of ash to a height of 4400 to 4700 meters above sea level, which dispersed in a north and northwesterly direction, accompanied by incandescent pulses between 150 and 300 meters high above the crater, weak and moderate avalanches channeled towards the barrancas Santa Teresa, Taniluyá, Ceniza, Trinidad, Las Lajas and Honda, some advancing to the limit of vegetation. Low, moderate and up to four loud rumblings were heard, causing sensitive shock waves up to 12 km from the volcano.

The lava flow towards the barranca Ceniza remains active, with an approximate length of 400 meters and the detachment of blocks in front.

 

Source: Insivumeh 08/28/2020

Fuego - 28.08.2020 - photo Conred

Fuego - 28.08.2020 - photo Conred

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