Volcanic activity world-wide 4-5 September 2012: Krakatau, Fuego, El Hierro, Popocatépetl, Nevado del Ruiz, Galeras, Sotará, Machin, Nevado del Huila, Tungurahua, Bagana, Batu Tara, Sakurajima

Krakatau volcano has been calm since 3 Sep. We posted some reports and photos from our expedition groups who happened to be there during 3-4 September.

Similarly, the latest stronger eruptive episode (paroxysm) of Fuego volcano ended after 32 hours yesterday afternoon INSIVUMEN reports in the last special bulletin this morning. During the peak of the eruption, Fuego produced lava flows reaching 1.5 km length as well as pyroclastic flows into Las Lajas canyon.

The earthquake swarm at El Hierro continues at modest intensity with now about 10 quakes per day, typically located at about 10 km depth in the western El Golfo area.

Tangkubanperahu volcano update: The Tangkuban Parahu nature tourism park was closed on Monday due to a rise in volcanic activity, the Jakarta Post reported. The alert level remains at 2 (out of 4).


Activity of Popocatépetl has remained stable during the past days with about 1 weak mostly steam explosion per hour. The crater is weakly glowing at night suggesting that slow growth of the lava dome continues. A significant SO2 plume from the volcano is visible on satellite imagery.

Seismic activity of Nevado del Ruiz volcano in Colombia has continued to decrease. The volcano is steaming and produces a large SO2 plume.

Weak seismic unrest continues at Cerro Machin volcano. Volcanic quakes concentrated SE of the main dome at depths between 3.0 - 9.5 km occurred during the past week.
Galeras remains calm. Only steaming has been observed recently.
Cumbal volcano had another weak seismic swarm on 30 August.
Nevado del Huila has remained stable with weak seismic unrest and steaming. SO2 flux has been calculated to 765 tonnes / day.
Sotará volcano continues to show some unrest as well, but less during the past week than before. The volcano has produced a total of 22 seismic events at shallow depths between 4-5 km in an area 1-2 km north of the summit. A possible inflation of the NE sector of the volcano is being detected on tilt meters.

Tungurahua volcano (Guatemala): Weak explosions with ash emissions have resumed. Incandescence can be seen at night during some explosions. The last one was reported at 23h36 (GMT) last night. Seismic activity has further increased until yesterday and has since decreased again. Over 500 small quakes and tremor pulses were recorded between 2-3 Sep. Strong SO2 emissions are being measured to 7-9,000 tonnes per day.

Satellite observations:

Bagana volcano (Bougainville Island, PNG) had a SO2 plume visible yesterday suggesting that activity has been higher during the past days.

Batu Tara produced ash plumes rising to 7,000 ft altitude yesterday and today.

Sakurajima volcano is known for its persistent activity, but also for very irregular intervals of explosions. There were 5 explosions on 3 Sep, sometimes 2 within an hour, but none yesterday and today so far.