Planchon-Peteroa and Sinabung Updates for 9/9/2010

Two volcanoes are keeping our attention right now:

Sinabung, Indonesia

Halfway around the world, activity at Sinabung continues to be cause for increasing concern. The volcano is experiencing larger and more frequent explosions. On Tuesday, the volcano produced what was described by government volcanologist Agus Budianto as “double the previous outburst and we recorded a tower of ash reaching 5,000 meters.” Many of the evacuees are voicing concerns that we have heard many times in these types of events – when will the scientists know what is going to happen next? Unfortunately, no one really knows what the volcano is apt to do. Surono, head of the Volcanology and Geological Disaster Mitigation Agency, said after the latest explosions “we now face uncertain conditions and we need to stay alert because nature can do anything.” Likely not the news that evacuees want to hear. Some residents are continuing to stay in their homes within the 6-km exclusion zone while others are returning to their homes after two weeks in shelters. Ash is falling (video) in many of the communities around the volcano, already effecting crops. You can check out a webcam for Sinabung to follow the activity as well (just click on the eye on the map, thanks to Eruptions reader Daniel Verhoef).

Top left: Sinabung erupting on September 7, 2010.

Planchon-Peteroa, Chile

As I mentioned the other day, Planchon-Peteroa (or just Peteroa) appears to be entering a new phase of activity over the last few days. Small explosions have been occurring at the summit, generating ash plumes that reach a few hundred meters (see below). This is been confirmed by the Chilean geological survey, the SERNAGEOMIN (spanish) and the alert status has been raised at communities near the volcano (spanish). The SERNAGEOMIN is also installing new monitoring equipment (spanish), including seismometers and cameras – and they are asking the local communities to keep a close watch for any changes in the volcanoes activity (and report it). There is an excellent gallery (spanish) of images taken September 7 from a flight over Peteroa showing the activity at the summit crater, including a small, brown plume and what looks like ash on the snow at the summit. All of the reports I have seen for this activity so far would indicate that Peteroa is in the early stages of a new eruptive cycle, with these explosions likely being phreatic events (flash-boiling of water by rising magma) that may be the precursors of explosive activity if the volcano follows its usual pattern (spanish). Be sure to check out the excellent coverage on Planchon-Peteroa at the Volcanism Blog as well.

A small ash plume from the summit crater at Planchon-Peteroa, Chile.