Colombia It was a busy week, volcanically-speaking, in the South American nation. We're talked about Nevado del Ruiz and the GVP mentions that the volcano has also shown changes in "deformation and geochemistry", which for the latter I assume means from the gases being released (but it could be water as well). Over at Nevado del Huila, the active summit dome produced plumes that reached up to 7.5 km / 25,000 feet along with incandescence and hot rock falls as part of a partial dome collapse (spanish).
Chile Planchon-Peteroa continues to produce ash plumes that reach as high as 3-6 km / 10-20,000 feet. Changing winds have raised considered of ash fall (spanish) in communities near the volcano, but ONEMI says there is no real danger (spanish). The volcano remains on Yellow Status - you can check out the latest SERNAGEOMIN report here (spanish - follow Region del Maule - Reportes - 2010)
Guatemala Fuego continues to experience explosions - and even an occasional lahar. This continues the pattern from earlier this summer. Pacaya also produced weak steam plumes as part of its continuing activity.
Kuril Islands It has been a while since we talked about Sarychev Peak - a big newsmaker in 2009 - but the volcano does continue to be active. Ash plumes were detected from the island volcano by satellite. Currently, remote sensing by satellite is the only monitoring for the remote volcano, which lacks any seismic monitoring.
Top left: A NASA image of Sarychev Peak after the 2009 eruptions.