Volcano activity of August 12, 2012 - Iliamna, Mount Rainier, Nevado del Ruiz, Gakeras, Popocatepetl, Fuego, Mt. Tongariro, White Island, Sheveluch, Turrialba and Rincon de la Vieja

This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Richard Wilson who specializes in Volcano seismicity and Armand Vervaeck. Please feel free to tell us about new or changed activity if we haven't written about it. -

August 12, 2012 volcano activity

Clusters of earthquakes occurred overnight at Iliamna (Alaska) and Mount Rainier (WA) volcanoes.

Nevado del Ruiz (Colombia) may be rousing from its recent sedate behaviour with some mild ash emission during the past 24 hours and bursts of volcano-tectonic earthquakes. (station OLLE)

Nearby Galeras volcano continues to experience explosions of gas and ash, but seismicity at the volcano is remarkably low. (station ANGV; the signal near the bottom of the record is volcanic tremor, the signal above in the record is a regional earthquake signal)

Tremor continues to be visible on seismograms at Popocatepetl volcano (Mexico), though eruptive activity at the volcano remains reduced. Seismic signals recorded today at Fuego volcano (Guatemala) imply eruptive activity continues there. (station FG3)

In New Zealand, seismicity is very low at newly active Tongariro volcano, while volcanic tremor continues at White Island volcano.

Satellite imagery shows enhanced SO2 output (w/ash?) from Popocatepetl (Mexico), Shiveluch (Kamchatka Peninsula), and Turrialba and perhaps Rincon De La Vieja (Coast Rica) volcanoes.