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 22, 2013 volcano activity
Seismicity remains high at Nevado Del Ruiz volcano (Colombia) (station OLLZ), with numerous magnitude M2.0 - M2.5 earthquakes overnight. Earthquake activity at the volcano has remained steady which may explain the lack of higher magnitude events (M3.0 - M4.0) observed during the previous two days. Those higher magnitude events followed/terminated periods of reduced earthquake activity at the volcano. INGEOMINAS reports strong degassing at the summit and occasional light ashfalls are reported by surrounding communities.
Numerous low-amplitude volcanic earthquakes have merged into essentially continuous volcanic tremor at San Cristobal volcano (Nicaragua) (station CRIN), and numerous small volcanic earthquakes (and tremor) continue at Telica volcano (station TELN).
KVERT reported no significant changes in seismic/eruptive activity at: Tolbachik, Sheveluch, Kizimen, Bezymianny, and Karymsky volcanoes (Kamchatka Peninsula) overnight. Moderate seismicity continues at hydrothermally active Gorely volcano.
Numerous rockfalls (signifying rapid lava dome growth) and occasional small pyroclastic flows affect Colima volcano (Mexico) again today. Exhalative activity is low (averaging less than one event per hour) at Popocatepetl volcano with low level volcanic tremor visible on seismograms there (as well as the magnitude M5.9 regional earthquake which struck the southwest coast of Mexico early today). Photographs from a recent overflight (16 April) by CENAPRED scientists shows the explosion crater excavated by recent explosive activity at Popo has already been filled by lava flows (a "pancake" lava dome).
Strombolian activity strengthened late this morning at Pacaya volcano (Guatemala) (station PCG), and strombolian activity has remained strong at Fuego volcano (station FG3) overnight. Volcanic ash-laden explosions have also been more frequent at Santiaguito Dome Complex (Santa Maria volcano) the past few days. Villages within a ten kilometer radius of both Fuego and Santa Maria have reported light ashfalls during that period.
Volcanic tremor recently increased at Masaya volcano (Nicaragua) (station MASN). Note that another brief increase oocurred as long-period surface waves from a distant earthquake passed the volcano. I have noticed this to be frequent occurrence at Masaya (especially with the recent flush of large earthquakes worldwide!).
What appear to be small volcanic earthquakes affect Poas volcano (Costa Rica) (station POA2) today.
Numerous tiny local earthquakes rattle Machin (Colombia) (station CIMA), Sotara (station SOSO), and Galeras (along with rockfall and gas emission events there) (station CUVZ) volcanoes today.
Small volcanic (?) earthquakes continue at Cotopaxi (Ecuador) (station CO1V). Similar small earthquakes have become apparent again on seismograms at Tungurahua volcano (station RETU). Co-eruptive(?) seismicity rumbles beneath/within Reventador volcano (station CONE) as well.
White Island volcano (New Zealand) continue to be afflicted with unsteady volcanic tremor today.
OMI satellite data were not updated again today. A single volcano (Tolbachik) was detected by MODIS satellite sensors during recent global transits.