Volcanic activity worldwide 22 Nov 2014: Stromboli volcano, Colima, Reventador, Dukono, Cerro Negro ...
samedi nov. 22, 2014 21:00 |
Strombolian acttivity at the summit vents of Stromboli (INGV)
Eruption column from yesterday's explosion at Colima (photo: Mario Anguiano M. / @gobernador_mam / twitter)
Stromboli (Eolian Islands, Italy): Lava effusion seems to have stopped completely since about a week ago. Small strombolian explosions continue to occur sporadically from vents in the northern and central crater terrace at the summit.
Infrared image of the lava flow on Reventador volcano on 10 Nov (IGEPN)
The apparent low activity may be the "calm before the storm": a surge in CO2 gas emissions since the beginning of November indicates that fresh magma might be on the rise within the conduit (CO2 being the least soluble magmatic gas and the first to leave the new magma).
One possibility is that the arrival of new magma leads to a strong initial (and very dangerous) explosion. This scenario occurred in 2003 and 2007 during similar stages of activity (after the end of a sustained lava flow).
Dukono (Halmahera): A series of stronger explosions and/or elevated ash emissions produced a plume at 8,000 ft (2.4 km) altitude extending almost 150 km to the west of the volcano.
Colima (Western Mexico): (22 Nov) A strong explosion occurred yesterday afternoon, producing a 5 km tall ash plume.
Ash fall occurred in up to 25 km distance in the municipalities of Zapotiltic and Tamazula de Gordiano.
The vulcanian-type eruption was likely the result of accumulated gas/magma pressure that ejected a solid plug blocking the vent.
Cerro Negro de Mayasquer (Colombia): The seismic crisis that began last year continues at high intensity. During the ongoing swarm more than 206,000 earthquakes have been detected in an area 4 km south of the Chiles-Cerro Negro complex since 29 Sep alone. Daily numbers of quakes have ranged between 3700-5400 earthquakes.
While most quakes have been very small, a few were strong enough to be felt by local inhabitants.
... [read more]
Reventador (Ecuador): A new lava flow is active on the upper NW flank of the volcano, originating from the base of its lava dome. Likely, the flow started in mid to late October; on 19 Nov, it had a length of less than 1 km.
vendredi, nov. 21, 2014
mercredi, nov. 19, 2014
Volcanic activity worldwide 19 Nov 2014: Shiveluch volcano, Kilauea, Sinabung, Dukono, Reventador, Copahue
lundi, nov. 17, 2014
Bardarbunga (Iceland): Winter conditions continue to make it difficult to study the fissure eruption at Holuhraun. Rare opportunities for visual observation however revealed that the Baugur crater ceased to eject tall lava fountains and transformed into an elongated, boiling lava lake. Magma seems to be welling up in this lava lake at the same effusion rate as early November. The two images accompanying this update are snapshots from a stunning video recently shot by Jon Gustafson. ... lire toutes
dimanche, nov. 16, 2014
vendredi, nov. 14, 2014
Volcanic activity worldwide 14 Nov 2014: Santiaguito volcano, Pacaya, Fuego, Ibu, Pavlof, Monowai, S...