Volcano activity of August 13, 2012 - Long Valley caldera, Bagana, Galeras, Sotara, Nevado del Ruiz, Tungurahua, Tongariro, White Island and Popocatepetl

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 13, 2012 volcano activity

A cluster of small (M<M2.0) earthquakes has developed overnight beneath the South Moat of Long Valley Caldera (CA).  The caldera's resurgent dome has been inflating since last summer.  (station MEM)
Exhalations of gases and ash have increased slightly (to an average of once per hour) at Popocatepetl volcano (Mexico) during the past day.  Weak volcanic tremor is visible on the Popo seismogram.
Volcanic tremor is again on the rise at Nevado Del Ruiz volcano (Colombia)  (station OLLE)
Pulses of volcanic tremor along with small earthquakes are apparent on seismograms from Galeras volcano (Colombia) today.  Galeras has produced vigorous expulsions of gases and ash during the past week.  (station ANGV)
Volcanic earthquakes appear to be on the wane at Sotara volcano (Colombia).  The Sotara volcanic system has shown signs of re-awakening since late June.  (station SOSO)
To the south,  Ecuador's Tungurahua volcano is again spewing gases and ash, judging from seismic and satellite data. (station RETU)
Across the Pacific, seismicity is nearly non-existent at newly active Tongariro volcano (New Zealand), while nearby White Island volcano trembles with continuous low-level volcanic tremor.
Satellite imagery indicates enhanced eruptive activity has occurred at Bagana volcano (Bougainville Island, PNG) in the past day.