Volcanic activity world-wide 30-31 August 2012: Little Sitkin, Etna, Iceland, Santiaguito, Popocatépetl, Nevado del Ruiz, Batu Tara, Sakurajima, Reclus

The Alaska Volcano Observatory moved Little Sitkin volcano in the western Aleutians to Yellow Alert following a strong earthquake swarm detected since late 29 August local time.

At Popocatépetl, weak steam explosions occur at frequencies of about 1 per hour. The largest reach about 1 km height and contain small amounts of ash. CENAPRED also registered a few small volcano-tectonic quakes on the evening of 29 and the morning of 30 Aug. Glow from the crater is visible at night.

Fuego and Santiaguito volcanoes in Guatemala have not changed much. Santiaguito had a moderately large explosion at 05:29 am today, that produced a gray ash column 900 meters high, moving southwest and causing ashfall 4 km in the Palajunoj areas. Incandescence was visible during the explosion. Weak avalanches from the southeastern lava flow continue.


Nevado del Ruiz volcano: Steam and sometimes ash emissions continue. Fluctuating tremor and small swarms of volcano-tectonic quakes are being recorded.

Karymski (Kamchatka): Occasional ash explosions occurred over the past week, producing plumes possibly up to 19,000 ft as mentioned earlier (25 Aug). KVERT reports moderate seismic activity.

A cluster of earthquakes (magnitudes 1.1-1.7), some at shallow depth occurred on 29 Aug a few km east of the summit region of Etna volcano under the Valle del Bove. Check the Etna earthquakes page for updates, location and maps of the recent earthquakes at Etna, which might give a hint if anything is preparing itself at the volcano, which otherwise seems fairly quiet these days.

A lot of earthquake activity took place on and near Iceland yesterday. At noon 30 Aug, a swarm with about 50 quakes partly preceded and followed a magnitude 4.2 quake at 5.8 km depth beneath the Reykjanes peninsula, near the axis of the the SW volcanic rift zone.
Another smaller swarm occurred north of the county on the Kolbeinsey Ridge. Earthquakes have been taking place in this area for several weeks already, but as the Iceland Volcanoes and Earthquakes blog notes, there seems to be an increase lately. In 1999, a volcanic dike intrusion or submarine eruption south of the nearby Spar Fracture Zone might have taken place.

Another volcano to watch now is Reclus volcano in southern Chile, located between Aguilera and Monte Burney in Patagonia. As the Eruptions Blog writes, an increase in local earthquakes has been noted recently.

Satellite observations:

Batu Tara (Sunda Islands, Indonesia) continues to have ash eruptions which occurred both today and yesterday and produced plumes rising to 7,000 ft, visible on satellite images drifting NW to distances of 40-60 km.

Sakurajima volcano has had only one explosion in the past 3 days span, at 01:36 am local time yesterday 30 Aug, but instead it was a bit larger than most in the past week and ejected an ash cloud rising to over 3 km altitude.