This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Rodger 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. -
April 21, 2013 volcano activity
Strong seismicity continues at Nevado Del Ruiz volcano (Colombia) (station OLLZ) today. Just as in previous days, volcano-tectonic earthquakes diminished in number through last night (although volcanic tremor amplitude increased) and then, following a magnitude M2.9 event this morning, resumed at its previous high level.
Another earthquake swarm, episode, pulse, whatever you wish to call it, is underway at Newberry volcano (Cascade Range) (OR) (station CPCO). This pulsatory seismic behavior has affected the volcano for nearly two weeks.
Seismicity has increased again at San Cristobal (Nicaragua) (station CRIN) and neighboring Telica (station TELN) volcanoes. Frequent low-magnitude volcanic earthquakes now merge into low-level volcanic tremor from time to time at the volcano. At Telica volcano, volcanic earthquake magnitudes have lessened, but event frequency is very high at this time.
KVERT reports no change in seismic/eruptive behavior at the five active Kamchatkan volcanoes: Tolbachik, Bezymianny, Sheveluch, Kizimen and Karymsky. Moderate seismicity affects hydrothermally active Gorely volcano.
Hybrid earthquakes, small explosions, rockfalls and pyroclastic flows continue at a high level at Colima volcano (Mexico). Activity at Popocatepetl volcano has diminished the past two days. Exhalations of gas (and occasional volcanic ash and blocks) now occurs only about once every two hours on average. The Popo seismogram shows only low level volcanic tremor at the volcano today.
Periods of more explosive activity have occurred this morning at both Fuego (Guatemala) (station FG3) and Pacaya (station PCG) volcanoes. Activity at Santiaguito Dome Complex (Santa Maria volcano) remains mostly internal (in the form of numerous hybrid earthquakes), but local inhabitants reported hearing jet-like noises coming from the volcano overnight.
Continuous volcanic tremor at Masaya volcano (Nicaragua) (station MASN) is slowly returning to background level.
Small earthquakes, rockfalls and degassing events (with ash?) are visible on seismograms recorded at Galeras volcano (Colombia) (station CUVZ) today.
Co-eruptive(?) seismicity remains high at Reventador volcano (Ecuador) (station CONE). Another episode of small earthquakes (volcanic? glacier?) affects Cotopaxi volcano (station CO1V).
Continuous volcanic tremor remains unstable at White island volcano (New Zealand).
OMI satellite were not updated again today. No volcanogenic "hotspots" were imaged by MODIS satellite thermal sensors today.