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. -
July 13, 2012 volcano activity
Seismic activity at El Hierro (Spain) continues its decline with no events (so far) stronger than a M2.8 today.
Another SO2 “bullseye” on Nyiragongo volcano (DR Congo) today. The SO2-rich plumes apparently are produced by increased magma/gas inputs and convection within the volcano’s perennial lava lake rather than true eruptive activity. Thanks to those who notified us with ground information, helping us dispel eruptive activity as the cause of increased SO2 output at the volcano.
Volcano-tectonic events, along with pulses of tremor affect Popocatepetl volcano (Mexico) again today. A small debris flow occurred high on the cone overnight.
Long trains of volcanic tremor have become more apparent at Pacaya volcano (Guatemala) in the past day (station PCG). I’m not sure if the increase is real or just an artifact of diminished telemetry interference which previously masked the activity.
The earthquake swarm we reported yesterday at Momotombo volcano (Nicaragua) has diminished overnight to just a few very weak events (station MOMN).
Meanwhile, in Colombia, tremor (or perhaps rockfall signals?), and small earthquakes are up again on seismograms from Galeras volcano (station ANGV). All’s quiet (seismically at least!) at Cumbal volcano, while numerous small, low-frequency events continue today at Sotara volcano (station SOSO). INGEOMINAS placed Cumbal in “yellow” alert stage this week because of increased seismic and thermal activity over the past few months and Sotara volcano is being watched after an intense earthquake swarm (nearly 900 events) occurred there at the end of June.