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. -
May 1, 2013 volcano activity
The recent quieting of volcano-tectonic seismicity at Nevado del Ruiz volcano (Colombia) (station OLLZ) ended late yesterday with a magnitude M3.8 earthquake centered (as were previous events) north of Arenas Crater. The earthquake was felt in surrounding communities, including Manizales some 30 km distant. VT seismicity at Ruiz has remained at a high level since the earthquake. Perhaps important, earlier large magnitude earthquakes (approaching and including magnitude M4.0 events) were focused beneath the epicentral area at or near 7 km depth. The focal depth for yesterday’s events was 5 km.
Update : INGEOMINAS posted some photos taken of the activity (strong degassing) yesterday at Nevado Del Ruiz. A magnitude M2.6 earthquake just occurred at the volcano and,…it too was located at around (5.61 km) 5 km depth!
KVERT reported the amplitude of volcanic tremor at Plosky Tolbachik (Kamchatka Peninsula) has risen slightly during the past 24 hours. Otherwise, eruptive/seismic behavior of the remaining four active Kamchatkan volcanoes: Sheveluch, Bezymianny, Kizimen, and Karymsky has not appreciabley changed. Seismic activity at Gorely volcano continues to hold at a moderate level in-tandem with a high level of hydrothermal activity at that volcano.
Short-lived episodes of shallow earthquakes continue at Iliamna volcano (Alaska Range) (station INE).
Another episode of small earthquakes occurred late yesterday at Newberry volcano (Cascade Range) (OR) (station CPCO). The episode appeared to be comprised of larger events and were in fact recorded by more than one Newberry seismometer. This is in contrast to earlier bouts of seismicity which have generally been picked-up by the closest sensor. Small earthquakes continue at the volcano today.
Still no updated seismic data for Colima volcano (Mexico). The average rate of occurrence for exhalation events (sometimes incorporating ash) at Popocatepetl volcano remains low, at less than one event per hour. Today’s Popo seismogram shows low-magnitude volcanic tremor, volcano-tectonic earthquakes, and exhalation events.
Explosive activity, strombolian in nature at both Fuego (Guatemala) (station FG3) and Pacaya (station PCG), and vulcanian in the case of the Santiaguito Dome Complex (Santa Maria volcano ) (station STG3) continue. The Fuego and Santiaguito volcanocams both captured recent explosions at each cone.
Bursts of higher amplitude volcanic tremor (and volcanic earthquakes) continue at San Miguel volcano (El Salvador) (station VSM). The bands of “noise” on each seismogram are the result of telemetry problems and not related to the volcano.
Tiny earthquakes at Poas volcano (Costa Rica) (station POA2) have tapered-off overnight.
Tiny volcano-tectonic events were recorded at Galeras (Colombia) (station CUVZ), Machin (station CIMA), and Cumbal (station MEVZ) during the past 24 hours. Small gas (and ash?) emission events also appear on the Galeras seismograms.
Continuous volcanic (degassing) tremor, occasionally punctuated by higher amplitude volcanic earthquakes affect Tungurahua volcano (Ecuador) (station RETU) again today. Spectrograms indicate degassing is slowly increasing at the volcano. Explosions/degassing at Tungurahua has thus far been largely ash-poor, and is further corroborated by recent volcanocam photos. Co-erupive(?) seismicity has declined somewhat overnight at Reventador volcano (station CONE). Recent volcanocam photos there (showing emission of a white plume) also point to relatively low explosivity.
Low-level volcanic tremor continues within/beneath White Island volcano (New Zealand).
Recent OMI satellite imagery shows SO2-enriched plumes wafting from Tolbachik and Ambrym (Vanuatu) volcanoes. MODIS satellite thermal imagers again detected significant “hotspots” only at Kilauea (Hawaii) and Tolbachik volcanoes today.