Volcano activity of July 4, 2012 – Canary Islands, Mexico, Guatemala, Colombia, Washington, Papua New Guinea and Philippines

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 4, 2012 volcano activity

Seismicity and deformation continues at El Hierro (Canary Islands) at rates comparable to those for the past week.  There is no apparent shallowing of earthquake hypocenters beneath the island and reports from earlier today about possible submarine gas emissions off the west coast of the island have been determined to be false.

Gas and ash emissions, accompanied by spasmodic tremor and small volcano-tectonic earthquakes affected Popocatepetl volcano (Mexico) again today.  Satellite images of SO2 emission at the volcano suggest a rhythmic pattern to exhalations there (though this may be partly due to meteorological factors).

Fuego volcano (Guatemala) has been restive the past few days with elevated levels of tremor (station FG3).

In Colombia, Galeras volcano continues to rattle with small earthquakes and short pulses of tremor (station ANGV).

There was a short (though small non-locateable earthquakes are still apparent on seismograms) burst of seismicity at around noon local time today at Mount Saint Helens volcano (WA)(station HSN).  Events were all less than M1.0 and located 3-4 km deep. There has been elevated crustal seismicity surrounding the volcano for the pas year.

RVO reported that four pyroclastic flows traveled down Manam‘s SE flank (Papua New Guinea) on 16 June. The following day activity was low; emissions were mostly steam with occasional ash. During 18-30 June gray ash clouds, that were sometimes black, rose 100-150 m above the crater and drifted mainly NW. Roaring and rumbling noises were sometimes reported. Incandescent tephra was ejected from the crater on most nights; activity during 28-29 June was almost Subplinian. Emissions from Main Crater were milder and mostly characterized by white and bluish plumes. Gray ash plumes were emitted during 18, 23, 26-27, and 29 June. Incandescence from the crater was visible during 18, 20-22, and 24 June. Ash fell in the NW part of the island.

Taal Volcano’s (Philippines) seismic network detected one (1)   volcanic earthquake during the past 24-hour observation period. Ground deformation survey (precise leveling) on the Volcano Island last 15 – 17 February 2012 indicated no significant change compared with October 2011, but is nonetheless still inflated compared with baseline data. GPS data for the period of February 2011 to end of May 2012 show steady deflation beginning in August 2011, but nonetheless also indicated that the edifice is still slightly inflated compared to February 2011 baseline data.

Manam volcano, Papua New Guinea – the volcano during an earlier eruption – Image by Nelson Toro

Mount Saint Helens map with epicenter locations

Mount Saint Helens, Washington seismicity graph July 4 2012

NOAA's SO2 satellite map showing the Popocatepetl volcano emissions on July 4 2012

Seismogram Fuego volcano, Guatemala

Seismicity at Galeras volcano, Colombia

El Hierro volcano, Canary Islands, Epicenter and Hypocenter map July 4 2012

El Hierro, Spain CHIE station seismogram on July 4 2012

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