Volcanos

Roundup of Global Volcanic Activity

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. 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): 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.

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.