Shikotsu (Hokkaido): The latest report of the Japan Meteorological Agency indicates some unrest at the caldera. Seismic activity accompanied by inflation were recorded under the western flank of Tarumai stratovolcano (the most active vent of the system, located on the SW rim of the Shikotsu caldera) between late June and early July this year.
Following this period of deformation, deep seismicity under the western flank has increased above background since the beginning of July. There are no reports of unusual surface phenomena.
Sinabung (Sumatra, Indonesia): Since the eruptions on 15 and 17 September, the volcano has been calm, but VSI warns that new eruptions could follow.
Such new eruptions are likely to follow the style of the last explosion, a sudden vulcanian-type eruption: it was proobably caused by accumulating viscous magma trapped under a solid plug in the crater, which was eventually disintegrated during an explosion when pressure exceeded the strength of the plug.
According to volcanologist Hendrasto, head of PVMBG, there are 29 villages at risk within a zone of 6 km radius around the volcano.
Popocatépetl (Central Mexico): Activity has remained at generally low levels with no large fluctuations. During 18-19 Sep, the number of small to moderate emissions has risen to about 2 per hour. Some of these events produced ash plumes up to about 1 km height, but frequent cloud cover prevented observation most of the time.
The most significant were registered at 01:01 h, 05:53 h, 08:10 h and 10:16 h (19 Sep) local time (see webcam video below):
Santa María / Santiaguito (Guatemala): Activity has been week with no significant changes. No explosions were reported during 18-19 Sep, but moderate rock avalanches could be heard, indicating that (some of) the lava flows on the flanks of the Caliente dome remain weakly active.
Pacaya (Guatemala): An increase in seismic activity has occurred gradually over the past 24 hours. Individual explosion signals have merged into strong continuous tremor. This could indicate another paroxysm with continuous explosions / lava fountaining / lava flow emission in the progress, but CONRED / INSIVUMEH have not (yet) updated on this possible increase in activity.
During the past days, the volcano had been producing frequent strombolian eruptions with jets of incandescent lava reaching 50-100 m above the Mackenney crater.
Fuego (Guatemala): No significant change in activity occurred over the past days. Small to moderate explosions that often are accompanied by shock waves occur from time to time (several times per day). Ash plumes rose up to about 600 m during 18-19 September.
Ubinas (Peru): While the volcano has calmed down at the surface since the series of 9 phreatic explosions during 1-5 September, a pulse of volcanic tremor yesterday could indicate that the volcanic crisis is not over or even still at the beginning.
The Geophysical Institute of Peru recorded changes in seismicity with the appearance tremor starting 02:00 local time on 18 September.
Even though the strength of the tremor signal is still small, it suggests that a body of new magma has started to heat up the hydrothermal system or is moving into the volcanic edifice. This in turn increased the likelihood of new and possibly magmatic eruptions (i.e. if the magma reaches the surface). – Volcano Discovery
Related articles
- Volcanoes Today, 19 Sep 2013: Reventador, Bagana, Klyuchevskoy, Kilauea (thesurvivalplaceblog.com)
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