Sunday 17 March 2013

Volcanos

Roundup of Global Volcanic Activity:


Etna (Sicily, Italy): The intensity of the (probably starting 8th paroxysmal) eruption is increasing relatively slowly, but steadily. At the moment, strong strombolian activity can be seen from the New SE crater. The volcanic tremor continues to rise exponentially (note the now logarithmic scale of INGV's tremor graphs). It seems that a new paroxysm is in the making. The tremor signal is showing a pronounced rise, typical for the beginning of the New SE crater paroxysms. Unfortunately, weather conditions don't currently allow visual verification.


Tolbachik (Kamchatka): (15 Mar) Tremor from Tolbachik remains high, although a bit lower today according to KVERT's daily update, and the eruption continues with lava effusion from the now single vent on the southern fissure. No significant changes were reported for any of the other volcanoes in Kamchatka: Moderate seismicity accompany dome building at both Sheveluch and Kizimen volcanoes. Seismic activity remains weak at Bezymianny, which also has an active dome and at Kliuchevskoi, where mild strombolian activity might still be going on in the summit crater.


Karkar (Northeast of New Guinea): (15 Mar) A larger explosive eruption from Karkar produced an ash plume rising to 28,000 ft (8.5 km). The plume is rapidly drifting NW.


Dukono (Halmahera): (15 Mar) A SO2 plume is visible on today's NOAA satellite data, suggesting a phase of elevated activity at the remote volcano.


Ambrym (Vanuatu): (15 Mar) SO2 emissions remain high.


Colima (Western Mexico): Activity at the volcano continues to increase. The new lava dome in the summit crater has apparently grown enough that incandescent lava could soon start descending into the Lumbre canyon on the western flank and produce pyroclastic flows, scientists from the university of Colima have warned. In a similar way, the Cordobán and Monte Grande canyons in southwestern and southern flanks are at increased risk, and Civil Protection has advised the population to avoid these valleys. The number of small explosions, rockfalls and volcanic quakes is on the increase.


Galeras (Colombia): (15 Mar) Activity has remained more or less unchanged, with occasional weak ash emissions and degassing observed at the crater. A magnitude 3.1 earthquake located 5.6 km WNW of the crater was recorded yesterday at 06:12:38 local time. In the past week, there were 2 seismic swarms with a total of 260 weak quakes on 11 and 12 March.


Nevado del Ruiz (Colombia): (15 Mar) During the last few days, INGEOMINAS has been recording weak continuous tremor of low energy and observed increased gas emissions, which produced a plume reaching up to about 1.5 km above the crater. The increased SO2 emission is also visible on NOAA's satellite images. Earthquakes associated with rock fracturing (caused by intruding magma at depth) remain in the same area as before, to the northeastern sector of Arenas crater, and to a lesser extent under the crater itself at depths between 2 and 6 km.


Reventador (Ecuador): (15 Mar) Activity fluctuates between relatively calm phases and strong ash emissions. In the evening of 13 March, a steam and ash column was seen rising 3 km above the crater.


Tungurahua (Ecuador): (15 Mar) Yesterday, IG the volcano showed an almost continuous emission of gas and various amounts of ash whose average height was 500 m. Individual explosions, sometimes accompanied by loud cannon-shot noises, produced eruption columns rising up to 3 km, mainly yesterday afternoon. At night, explosions increased again and incandescent blocks were seen ejected to up to 500 m below the crater rim.


Sacabaya (Northern Chile, Bolivia and Argentina): (15 Mar) INGEMMET reports increased fumarolic gas emissions (but no ash so far) creating a gas column rising 400 to 1000 meters above the crater. The report also mentions that since 28 Feb, there has been an average number of 400 to 500 earthquakes per day, mostly volcano-tectonic quakes related to rock fracturing in return probably related to intruding magma at depth. The volcano remains closely monitored.

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