Roundup of Global Volcanic Activity
Batu Tara (Sunda Islands, Indonesia): We just returned from a 3-days expedition to the island during 23-26 Nov: the volcano’s activity was overall at similar levels as during the previous visits between 2012-June this year, but highly variable from day to day: Phases lasting several hours, or even few days, with mild, ash-rich strombolian eruptions at intervals between 10-30 minutes alternated / were interrupted by much more powerful vulcanian-type explosions that produced shock waves and ejected dense columns of tephra (ash, blocks and incandescent lava bombs) in a single, cannon-shot like explosion. They sent ballistics to several hundred meters of height all over the upper half of the volcano. During the first two observation days, these explosions occurred at intervals between 3-10 hours, but became the dominant type of activity during the last 24 hours of our stay, when they occurred at shorter intervals of 1-2 hours typically.
Telica (Nicaragua): After its powerful explosion on 22 Nov, the volcano has mainly been calm, but weaker, sporadic ash emissions resumed during the past days. It is still thought that the recent activity is only caused by over-pressurized fluids in the upper conduit, and doesn’t involve new magma, but comparing with the past episodes of explosive activity in May and September this year, it is almost likely that new, potentially strong and very dangerous explosions (in particular if you climb the volcano) could follow in the near future with no or little warning.
Copahue (Chile/Argentina): Small to moderately strong ash emissions and explosions have been near continuous during the past days, creating steam/ash plumes that rise up to approx. 1 km. Overall, the volcano’s activity seems to be gradually increasing. A larger landslide occurred yesterday from the eastern flank.
Etna (Sicily, Italy): Since Nov 25 there is a change visible in Etna’s activity. Weak strombolian activity has started from the New SE crater. The activity probably started earlier today, but due to bad weather it was not observed before. Weak strombolian activity continues also from the vent inside the Voragine crater. Tremor remains low at the moment.