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. -
January 26, 2013 volcano activity
KVERT reports no appreciable changes in eruptive activity at the Kamchatkan volcanoes. Lava extrusion continues at Tolbachik, Kizimen, Sheveluch, and Bezymianny with accompanying seismic activity ranging from high (at Tolbachik) to low levels (at most of the remaining vents). Strombolian explosive activity continues at the summit of Kliuchevskaya Sopka, and Strombolian to Vulcanian explosions occasionally rock Karymsky volcano. Moderate levels of volcanic tremor and volcanic earthquakes shudder beneath Gorely volcano which exhibits a high level hydrothermal activity at this time.
Small local earthquakes (interspersed between decreasing regional aftershocks) are still visible on seismograms from Tanaga volcano (Aleutian arc) (station TASE). Seismicity has increased dramatically at or near Katmai volcano (Alaska Peninsula) (station KBM) in the past 24 hours, and small earthquakes are more frequent once again at Iliamna volcano (Alaska Range) (station INE) during the same period. Many of the event locations shown on the Iliamna map date from an earthquake swarm at the volcano on 29 December 2012, but the recent earthquakes occur in the same general location (southwest flank).
A new cluster of earthquakes has formed beneath the western flank of Mammoth Mountain volcano (CA) (station MMS) in the past day. The event cluster is focused around 6 km depth.
Small explosions, rockfalls and volcanic earthquakes have increased at Colima volcano (Mexico) overnight, as have exhalations (of gas and small amounts of ash) at nearby Popocatepetl volcano. Emissions at the volcano now occur at an average rate of nearly three per hour. Seismicity is relatively high at the volcano, with numerous earthquakes and volcanic tremor visible on today's Popo seismogram.
Emissions of gas and ash are frequent at Santa Maria volcano (Guatemala) (station STG6) today, but seismograms from the volcano show little energy being expended. Activity at nearby volcanoes Fuego and Pacaya remains subdued.
Seismicty at San Cristobal volcano (Nicaragua) (station CRIN) now approaches "background" levels with frequent volcanic earthquakes and low-level volcanic tremor. I will discontinue reporting on San Cristobal today until there is a significant change in the volcano's internal/external behavour. The large (blue) event on the San Cristobal record is a regional tectonic earthquake. What appear to be small volcano-tectonic earthquakes have appeared on seismograms at Concepcion volcano (station CONN) this morning.
A swarm of volcanic earthquakes (within increased volcanic tremor) that began two days ago at San Miguel volcano (El Salvador) (station VSM), appears to be on the decline. There are also regional tectonic earthquakes (large "green" event) visible on San Miguel records.
I am still not able to access seismic data for the Colombian volcanoes. I wish I could as there has been a fairly strong SO2 anomaly centered on Nevado Del Ruiz volcano during the past day.
Co-eruptive seismicity appears to have diminished dramatically overnight at Reventador volcano (Ecuador) (station CONE), but there is the suggestion of equipment malfunction as well.
SERNAGEOMIN reports another earthquake swarm, consisting of some 80 volcano-tectonic and low-frequency earthquakes, at Copahue voclano (Chile-Argentina border) overnight. This is in addition to 26 other volcano-tectonic earthquakes, continuous volcanic tremor and over 2000 non-classified events (believed to be related to the degassing process) which occurred at the volcano during the same period.
Hybrid earthquakes (red spikes) (related to fluid movement) have continued to increase (within continuous, strong volcanic tremor) at White Island volcano overnight. Numerous small earthquakes dot seismograms at both Tongariro and Ruapehu volcanoes this morning.
Recent satellite imagery shows SO2-enriched plumes drifting from Tolbachik, Popocatepetl, Nevado Del Ruiz, Nyiragongo (DRC), and Ambrym (Vanuatu) volcanoes.