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 29, 2013 volcano activity
KVERT reported no significant changes in eruptive/seismic behavior at the five active Kamchatkan volcanoes: Tolbachik (basaltic fissure eruption - high seismicity), Sheveluch and Kizimen (lava flow/dome extrusion - moderate seismicity), Bezymianny (lava flow/dome extrusion - weak seismicity), and Karymsky (occasional strombolian/vulcanian explosions - no seismic data due to monitoring equipment outtages). Moderate seismicity also affects Gorely volcano which exhibits a high level of hydrothermal unrest.
A short-lived burst of seismicity occurred at Iliamna volcano (Alaska Range) (station INE) overnight, including a magnitude M2.0 earthquake.
Small earthquakes were also recorded at Mount Hood and Newberry volcano (Cascade Range) (OR).
Low-level seismicity (both shallow and deep) also continues at/near Mammoth Mountain volcano and Long Valley Caldera (CA) (station MRD) this morning.
Still no updated seismic data from Colima volcano (Mexico), but this morning's Colima volcanocam photo shows a pyroclastic flow descending the flank of the Fuego cone. Activity has been high at Popocatepetl volcano the past two days. Exhalations of gas and some ash (occasioanllly punctuated by larger blasts of lava blocks and ash) now occur at an average rate of nearly three events per hour. The Popo seismogram shows a period of spasmodic tremor, exhalation signals and small volcano-tectonic earthquakes affecting the volcano today.
Numerous low-frequency "chugging" earthquakes affect Pacaya volcano (Guatemala) (station PCG) today. Periods of volcanic tremor and occasional small strombolian explosions characterize activity at Fuego volcano (station FG3), and relatively low external activity affects the Santiaguito Dome Complex (Santa Maria volcano) (station STG3), though tremor has recently increased at the volcano.
Volcano-seismicity has recently returned to (or at least, approaches!) background level at Nicaraguan volcanoes: San Cristobal (station CRIN), Telica (station TELN), and Masaya (station MASN) during the past few days.
Volcanic earthquakes continue to be frequent at San Miguel volcano (El Salvador) (station VSM) this morning.
Small earthquakes (likely associated with heating of the crater lake there) continue at Poas volcano (Costa Rica) (station POA2).
Following a brief hiatus over the weekend, seismic unrest has once again increased at Nevado Del Ruiz volcano (Colombia) (station OLLZ).
Strong explosions signals punctuate the seismic record this morning at Tungurahua volcano (Ecuador) (station RETU). Inclement weather prevents viewing the activity, but the clouds did briefly part last night, affording some picturesque photos of the volcano both at rest and in eruption. Small earthquakes continue in varying daily numbers at Cotopaxi volcano (station CO1V). The daytime seismogram (seismic monitoring at the volcano is affected by a weak battery and is only functional during daylight hours when power is supplied by solar panels) at Reventador volcano shows strong (co-eruptive?) seismicity occurring at the volcano today. A recent Reventador volcanocam photo shows only a white gas plume (SO2) over the cone, suggesting the activity is primarily effusive.
GNS has reduced the aviation alert level at White Island volcano (New Zealand) from "yellow" to "green", indicating that the volcano has returned to a relatively quiescent state. Today's White Island seismogram shows relatively low-level (but continuous) volcanic tremor and some tiny local earthquakes. An observation flight over the island this past weekend revealed that the previous two crater lakes have merged, "drowning" the recently active vent.
Recent MODIS satellite thermal imagery depicts volcanogenic "hotspots" at Tolbachik volcano.