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. -
March 12, 2013 volcano activity
KVERT reports no significant changes occurred in eruptive behavior at the six active Kamchatkan volcanoes: Tolbachik, Kliuchevskoi, Bezymianny, Sheveluch, Kizimen, and Karymsky overnight. Seismicity (associated with strong geothermal activity) remains at a moderate level at Gorely volcano.
Flurries of small earthquakes affected Mount Saint Helens (station VALT) and Mount Hood (station TDH) volcanoes during the past day. I have recently noticed frequent small local earthquakes on seismograms from monitors on the north flank of Mount Shasta (stations LMP and LBO). The small events may be glacier quakes eminating from either the nearby Hotlum or, more likely, Whitney glaciers (…or not!).
Activity at Colima volcano (Mexico) continues to increase. Explosions occurred quick succession (minutes apart) at the volcano early today. Expulsions of gas, occasionally mixed with volcanic ash, occur an average of more than once per hour at Popocatepetl volcano today. A volcano-tectonic earthquake swarm continues beneath the cone (the larger event is a regional earthquake).
INSIVUMEH reports small gas and ash bursts have become frequent the past few days at Pacaya volcano (Guatemala), suggesting that continuous strombolian activity may return at MacKenney crater in coming weeks. Moderately explosive strombolian activity at Fuego volcano resulted in light ashfall up to 10 km from the vent (at Panimache and Morelia villages today). Explosions were heard up to 6 km from Fuego as well. At Santiaguito Dome Complex (Santa Maria volcano): four active lava flows (on the southeast, south, southwest, and northwest flanks) continue to descend the Calient dome. Vulcanian explsions occur between 40 and 60 times per day at the volcano, accompanied by constant rockfalls and occasional small pyroclastic flows. Occasionally larger vulcanian explosions lift ash to between 3000 and 3500 meters height. Today, light ash from Santiaguito is falling over Quetzaltenango. Seismic data from the Guatemalan volcanoes was unavailable at the time of this writing.
A few stronger volcanic earthquakes dot current seismograms from San Cristobal volcano (Nicaragua) (station CRIN). Small volcanic earthquakes are apparent on seismograms from Momotombo volcano (station MOMN), and,…to illustrate how noting seemingly minor changes in seismic behavior pays-off (see the past few reports,…and note the 12 previous hours of complete “quiet” at the volcano), a strong harmonic signal recorded at Concepcion volcano (station CONN) suggests either an eruption occurred there a few hours ago, or may be in the offing. Another seismic crisis (or, at least continuation of previous episodes!) is underway at Telica volcano (station TELN). This volcano bears close watching as well.
Relatively strong volcanic earthquakes continue to be frequent at San Miguel volcano (El Salvador) (station VSM).
Local earthquakes are taking place at/near Poas (station POA2) and Irazu (station HAYA) volcanoes (Costa Rica) today.
Continuous, low-level harmonic tremor (punctuated by a few earthquakes) continues at Nevado Del Ruiz volcano (Colombia) (station OLLZ). Short periods of higher amplitude tremor have occurred at the volcano through this morning. Numerous small earthquakes continue at Machin volcano (station CIMA), and bursts of volcanic tremor and small earthquakes (possible accompanied by ash emission) have occurred at Galeras volcano (station CUVZ) through the time of this report.
Co-eruptive seismicity continues at a moderate to high level at Tungurahua volcano (Ecuador) (station RETU). EPN reports that deformation (as measured by GPS) at the volcano is minor and likely results from gas transients within the volcano’s plumbing rather than significant magma intrusion. Seismicity at Reventador volcano (station CONE) alternates between relative quiet and moderate to strong volcanic earthquakes and tremor. A few local earthquakes are visible on seismograms recorded at Cotopaxi volcano (station COV1).
Small earthquakes are not as prominent (embedded in very low-level volcanic tremor) today at White Island volcano (New Zealand).
Recent OMI satellite imagery shows significant SO2-enrich plumes eminating from Nevado Del Ruiz and Tungurahua volcanoes. A relatively modest-sized plume drifts from Nyiragongo volcano (DRC), and weak, possibly spurious SO2 anomalies occur at Sabancaya (Peru) and Etna (Italy) volcanoes. Again, there were no updates to MODIS satellite thermal imagery today.