Volcano activity of April 6, 2013

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 6, 2013 volcano activity

Seismicity has steadily declined during the past 24 hours along the Tjornes Fracture Zone (Iceland), with one M3.0 earthquake being the highest magnitude event recorded during that period.

Earthquake activity (with occasional pulses of volcanic tremor) remains high at Telica volcano (Nicaragua) (station TELN).

Elsewhere,...

KVERT reports no significant changes in eruptive/seismic behavior of five active Kamchatkan volcanoes: Tolbachik, Sheveluch, Bezymianny, Kizimen, and Karymsky overnight.

kizimen_ali_20130312

tolbachik_ali_20130306

Tolbachik_MODIS_Hotspots_20130406

In yesterday's report we noted a burst of seismicity (with volcanic tremor) at Korovin volcano,...well, today we note similar activity at another Aleutian arc volcano,...Tanaga (station TASE).  Both local and regional seismicity has been elevated at Tanaga for some time.

Activity (in the form of hybrid earthquakes, small explosions and rockfalls) has been very high during the past 24 hours at Colima volcano (Mexico).  Recently, nearly continuous low-magnitude rockfall signals have become predominate on seismic records at the volcano, suggesting steady extrusion of de-gassed lava is now taking place.  Continuous volcanic tremor also affects Popocatepetl volcano today. Exhalation events are also visible on the Popo seismogram.

popoTlamacas20130406

Volcanic tremor has diminished at Pacaya volcano (Guatemala) (station PCG) overnight.  Strombolian explosions have increased in frequency at Fuego volcano (also affected by tremor) (station FG3), and activity (in the form of numerous hybrid earthquakes) remains mostly internal at Santiaguito Dome Complex (Santa Maria volcano) (station STG3).  One explosion was heard overnight at the volcano.  Light ashfall was reported today at villages in the vicinity (within 15 km radius) of both Fuego and Santa Maria volcanoes.

Fuego_20130406

Santiaguito_20130406

Unsteady volcanic tremor and a few volcanic earthquakes (and possibly a small explosion signal) were recorded overnight at Masaya volcano (Nicaragua) (station MASN).

Volcanic earthquakes embedded within continuous low-magnitude volcanic tremor continue at San Miguel volcano (El Salvador) (station VSM).

Small events, interpretted here as small hydrothermal explosions, continue to punctuate seismic records at Poas volcasno (Costa Rica) (station POA2).

Small earthquakes have again become numerous on seismograms recorded at Nevado Del Ruiz volcano (Colombia) (station OLLZ).  Small local earthquakes have also re-appeared on seismograms from Machin volcano (station CIMA).  Activity has increased overnight at Galeras volcano (station CUVZ) with numerous gas emission signals and a nearly 15 minute pulse of (emission?) tremor.  A swarm of small volcano-tectonic earthquakes continues at Cumbal volcano (station MEVZ) as well.

Volcanic earthquakes continue to diminish in magnitude and rate of occurrence at Tungurahua volcano (Ecuador) (station RETU), while periods of relatively strong (and likely co-eruptive) volcanic earthquakes and tremor afflict Reventador volcano (station CONE).

IGP has issued another report on activity which details the now clearly declining unrest at Sabancaya volcano (Peru).  I have included photos and diagrams from the report here.

Sabancaya_fumarole_20130404

Strong, continuous volcanic tremor (with a few embedded hybrid earthquakes) has returned at White Island volcano (New Zealand).

Recent OMI satellite imagery shows SO2-enriched plumes issuing from Tolbachik, Ambrym (Vanuatu), and Manam (New Guinea) volcanoes today, while the only "hotspot", as detected today by MODIS satellite thermal imagers, also occurred at Tolbachik volcano.