Sunday, 30 December 2012

Volcanos

Global Volcanic Activity:


Pacaya volcano in Guatemala is waking up. A series of 3 small explosions occurred yesterday morning and generated small ash plumes rising 500 m. The explosions were probably phreatic, but along with the previous explosions 10 days ago they likely indicate that magma has started to rise within the volcano and might reach the surface soon again. Strombolian and/or lava flow effusion activity, Pacaya's typical activity, could thus resume in a relatively short time.


Activity at Fuego volcano has remained essentially unchanged with weak strombolian explosions (11 counted during 28-29 Dec) producing small ash plumes up to about 500 m high, and the continuing lava flow, about 500 m long on the upper southern slope.


The Santiaguito lava dome has been comparably calm with few or no explosive activity reported during the past days.


The number of small explosions and steam-ash emissions from Popocatépetl volcano in Mexico remains at moderate levels (1-2 per hour). Glow from the crater indicates that the slow magma supply to the crater continues.


Activity at at San Cristobal volcano in Nicaragua has calmed down, at least for now. Only few and weak new ash emissions occurred since the afternoon of 28 Dec, and current seismic activity is low.


At nearby Concepcion volcano, an increase in small volcanic quakes can be seen on recent seismograms.


Arenal volcano in Costa Rica showed some elevated internal activity on 29 Dec, but has been calm again today.


Mild ash explosions continues to occur sporadically at Galeras volcano in Colombia, such as recently seen on 29 Dec.


An SO2 plume drifting from Nevado del Ruiz volcano shows ongoing intense degassing. INGEOMINAS reported occasional steam and ash venting. Small earthquakes and occasional low-level volcanic tremor pulses can be seen on the seismic recordings.


Seismic unrest with small deep (12-15 km) quakes continues at Cerro Machin volcano.


In Ecuador, activity at Tungurahua volcano has picked up again. During 29 Dec, 30 explosions over 24 hours of small to moderate size, sometimes accompanied by loud sounds and ejection of incandescent material. Ash plumes were reported reaching 25,000 ft (7.5 km) altitude. Numerous volcanic quakes and tremor pulses accompanied constant gas and ash emissions.


At Reventador volcano, sporadic small explosions and ash emissions continue, but at lower levels than during past months.


Visual and seismic activity have decreased at Copahue volcano in Chile. No more ash emissions or incandescence have been observed since 29 Dec. It is thought that the small eruption that had started on 22 Dec has ended. The small body of lava (a lava dome) that was emplaced inside the crater is now cooling. SERNAGEOMIN has lowered the alert level to yellow.


The lava flows from the southern fissure of Plosky Tolbachik volcano in Kamchatka continue to be alimented and KVERT reports that tremor is still strong (although much less than 1-2 weeks ago). The plume and visible glow from the eruption are smaller as well but still present.


MODIS satellite data continue to show a hot spot at Australia's Heard Island volcano. This indicates that some activity is probably present at this volcano.

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