GVP Weekly Volcanic Activity Report for September 7-13, 2011: Canaries rumbling and lots in Indonesia
Our somewhat quiet (beyond Etna’s frequent paroxysms – and the cool lava “spine” that formed after the last one) volcanic fall continues. We have been following a lot of rumbling around the world – and we’ve seen some minor eruptions – but all in all, September has been a fairly low-key month when it comes to volcanic activity.
This week’s Global Volcanism Program Weekly Volcanic Activity Report from the Smithsonian Institute and the USGS is a little busier than previous weeks, so let’s check out some highlights:
Canary Islands: For the first time this year, the seismicity at El Hierro has made the report. The volcano, as many of you know, has been experiencing increased seismicity since June, with over 6,200 earthquakes thus far, along with increased carbon dioxide emissions as well. However, beyond this there have been little in the way of other signs that an eruption in coming soon – Cabildo de el Hierro* still has El Hierro on green alert status, even with all this seismicity.
*Correction: Is it actually the Cabildo de el Hierro that defines the alert status for the volcanoes, not AVCAN (Actualidad Volcánica de Canarias) or Involcan.
Indonesia: We can add Ranakah on Flores Island in Indonesia as another volcano to watch. Ranakah is a dome complex that most recently saw a VEI 3 eruption in 1987 when the youngest dome was formed. Right now, small steam plumes and increased seismicity have prompted the PVMBG to raise the alert status to 2. Ranakah isn’t the only Indonesian volcano to see its alert status go up, as Tambora was raised to alert status 3 after continued rumbling – preparations for possible evacuations are underway by the Regional Disaster Mitigation Agency (BPBD) of West Nusa Tenggara. Even Merapi has been puffing away, producing diffuse ash plumes along with GVP Report regular Dukono. Finally, Soputan, saw a marked decrease in activity so the alert status there was lowered to 2.
Top left: An undated view along the shoreline at El Hierro. Image by Rafa Micamara.