Volcanic activity world-wide 20 August: Tungurahua, El Hierro, Popocatépetl, Nevado del Ruiz, Krisuvik, Batu Tara, Sakurajima
http://www.volcanodiscovery.com/view_news/13259/Volcanic-activity-world-wide-20-August-Tungurahua-El-Hierro-Popocat%C3%A9petl-Nevado-del-Ruiz-Krisuvik-B.html
The eruption of Tungurahua volcano continues with constant ash emission rising 1.5 km above the crater, intermittent moderate explosions, and produces pyroclastic flows of 1.5 km length.
The seismic swarm at El Hierro island continues, but the number of quakes has been decreasing. Yesterday, only 8 weak quakes (all below M2) were recorded. Today there have been 5 quakes so far, and it seems that the strength of the earthquakes is increasing, the latest quake today being a M2.7 event at 20 km depth under the western tip of the island.
The activity of Popocatépetl in Mexico has decreased again after the increase of explosions on 18 Aug. The number of (mostly small) explosions has dropped from about 4 per hour during 18-19 Aug to only one every 2 hours during 19 Aug. A strong SO2 plume was visible on yesterday's NOAA image.
Steam and ash emissions accompanied by varying tremor continue at Nevado del Ruiz volcano in Colombia, some of the seismic stations are out of function due to ash fall. A new series of small quakes SE from and at 1.5-2 km depth beneath Arenas crater has been recorded.
A seismic swarm occurred at Krisuvik volcano in SW Iceland on 18 Aug. More than 40 quakes (mostly very small) occurred at around 5 km depth beneath the volcano. The number of quakes has dropped since.
Batu Tara (Sunda Islands, Indonesia) volcano continues to show up in Darwin's VAAC messages notifying about ash plumes reaching 7,000 ft (2.1 km) altitude.
Sakurajima volcano produced 3 more weak explosions with ash clouds reaching 2.4 km altitude during the past 24 hours.
