Volcano activity of February 21, 2013 - Iliamna + Etna now erupting during daylight ! (video)

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. -

February 21, 2013 volcano activity

Etna had it's 4th paroxysm earlier today, this time during daylight. The YouTube embedded video shows the volcano action of the 3th, yesterday, in a great way. Enjoy the Salvo Orlando video (www.sicilylandscape.com).

Etna_MODIS_Hotspots_20130221

KVERT reports no significant changes in eruptive behavior at the six erupting Kamchatkan volcanoes. Seismicity remains relatively high at Plosky Tolbachik (lava fissure eruption), moderate at Kizimen (lava flow/dome emplacement), and Karymsky (occasional strombolian/vulcanian explosions), and weak at Kliuchevskoi (weak strombolian explosions), Sheveluch (lava flow/dome emplacement and occasional vulcanian/pelean explosions) and Bezymianny (lava flow/dome emplacement with occasional vulcanian/pelean explosions).  Seismicity related to strong degassing continues at Gorely volcano. Recent MODIS satellite thermal imagery shows a multi-pixel anomaly corresponding to recently emplaced lava flows at Plosky Tolbachik.

Tolbachik_MODIS_Hotspots_20130221

Small earthquakes (and telemetry interference!) remain frequent at Alaska Range volcanoes Iliamna (station INE) and Mount Spurr (station CKT).  Recent clear views of Iliamna (especially rare at this time of year!) have confirmed that a large avalanche/debris flow occurred recently at the volcano (likely on 02 February,...see our report for that date).  The avalanche sourced in a "disturbed" area on the Red Glacier identified by AVO in March 2012 (all photos are by AVO except debris flow photos which were captured by local photographer Dennis Anderson).  The glacier disturbance appears to have formed in-concert with the onset of unrest at Iliamna beginning in late 2011.  The recent large avalanche occurred as another bout of strong earthquakes (maximum magnitude M3.1) struck the peak in early February.  A smaller debris flow issued from the area in October 2012.  It is likely that the initial glacier break-up was precipitated by increased thermal output (perhaps in pulses during enhanced seismicity) at the glacier sole.  Increased thermal output, as well as increased magmatic gas output at Iliamna was verified early in the current period of unrest during overflights by AVO.  I am speculating here but, the large debris flow could have been set into motion by small changes in slope on the volcano's flanks that may have occurred (accelerated?) during this latest earthquake swarm.  Located earthquakes that make-up the early February swarm suggest magmatic dike injection is focused south of the avalanche source, but interestingly, the strongest events locate directly beneath the Red Glacier disturbance.  As I mentioned in the 02 February report, avalanches of this size are not unusual at Iliamna, but recent events beg at least some (increased) volcanic influence!

Iliamna_seismicity_20130221

Red_Glacier_disturbance

13_October_2012_debris_flow

Image courtesy and copyright Dennis Anderson

Swarm_epicentral_area

Small earthquakes (maximum magnitudes <M2.0) continue along the southern boundary of Long Valley Caldera (CA) (station MCM), especially in the Convict Canyon area (Sierra Nevada) south of the Mammoth Airport.  A few of the events on today's record are aftershocks from the M5.1 which struck western Nevada last week.

Long_Valley_seismicity_20130221

Exhalations of gas and some volcanic ash continue at a reduced rate at Popocatepetl volcano (Mexico), averaging less than once per hour.  Today's Popo seismogram shows low-level volcanic tremor and small local events, but most prominent is the M5.8 Coahuayana regional earthquake.

imagenPopoTochimilco_20130221

Pacaya volcano (station PCG) continues to have the most interesting seismograms of the three active Guatemalan volcanoes.  The volcano continues to "perk" with numerous small volcanic earthquakes and occasional pulses of tremor.

San Cristobal volcano (Nicaragua) (station CRIN) experienced periods of banded tremor overnight.  Nearby Masaya voclano (station MASN) also exhibits periods of elevated volcanic tremor.

Volcanic tremor has also increased slightly at San Miguel volcano (El Salvador) (station VSM).

Small earthquakes (and short pulses of tremor at Galeras) affect three Colombian volcanoes: Ruiz (station OLLZ), Machin (station CIMA), Galeras (station ANGV), and Cumbal (station MEVZ) today.

Sustained low-level volcanic tremor with occasional flurries of volcanic earthquakes (as well as equipemnt malfunction!) continue at Reventador volcano (Ecuador) (station CONE).  A flurry of volcanic earthquakes also occurred at Cotopaxi volcano (station CO1V) overnight.

Volcanic tremor has risen to its highest level since unrest began at White Island (New Zealand) last year.  Volcanic earthquakes also remain frequent at the volcano.  What appears to be a pulse of volcanic tremor occurred overnight at Tongariro volcano.  Tiny local earthquakes are apparent on seismograms recorded at nearby Ruapehu volcano.

Recent OMI satellite imagery shows SO2-enriched plumes wafting from Popocatepetl, Turrialba (Costa Rica), Bagana (Solomon Islands), and Sakurajima (Japan) volcanoes.  MODIS satellite thermal imagery reveals multi-pixel "hotspots" at Tolbachik and Etna (Italy) volcanoes.