Volcano activity of August 10, 2012 – Popocatepetl, Sotara, Galeras, Tungurahua, Sakurajima, Bagana, Etna, Ambrym and Mount Pagan

This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Richard 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. -

August 10 , 2012 volcano activity

Update 22:13 UTC : Volcanic earthquakes at Etna volcano have further increased and are putting an incandescent show on the streaming webcam from Etna Walk

Rodger Wilson, back from his field job writes :

Well, I guess I’m not the only one suffering from “technical difficulties” today. None of the seismograms recorded at any of the Colombian volcano observatories have updated, and seismograms from the Guatemalan volcanoes are cluttered with electronic interference of some sort. Even the Popocatepetl seismogram suffers from that repetitive pattern produced by a software “glitch” I’ve mentioned before.

Anyhow, Tremor appears quite strong at Popo today, even though gas and ash emissions have fallen-off the past few weeks at the volcano. (note the repeating pattern in the tremor caused by the “glitch”).

Ash eruptions continue at Galeras (Colombia) but there has been no general increase in seismicity at the volcano either before or during this current episode of ash emissions which is what makes this volcano so interesting to observe (…and dangerous!). (station CUVZ) (barranco photo) Nevado Del Ruiz (Colombia) continues to periodically release plumes of SO2 admixed with some ash.

INGEOMINAS (Colombia) released a report yesterday on the on-going seismicity at Sotara volcano since the vigorous earthquake swarm there in late June. The fact that seismicity is on-going indicates that the Sotara volcanic system has indeed re-awakened (there are no historically documented eruptions at the volcano) and bears a close watch.

While I was in the field, I missed a significant (volcano?)-tectonic earthquake swarm on the Alaska Peninsula, another relatively small earthquake swarm at Yellowstone, and, of course, the re-awakenings of Tongariro and White Island in New Zealand. Speaking of which, at Tongariro, small earthquakes continue beneath the new eruptive fissure (the larger quakes are regional earthquakes) and continuous hydrothermal(?) tremor affects White Island today.

After 3 days of very reduced seismicity, volcanic earthquakes at Etna volcano, Sicily are increasing again

Galeras volcano emits a strong ash cloud – Barranca image

Activity observed by satellites
No more advisories on Batu Tara volcano, Indonesia as the activity of the volcano probably subsided
VAAC Tokyo reports that Sakurajima volcano (Japan) had its last explosion at 15:25 UTC today (see also SO2 image)
Th VAAC Washington bureau reports that a Ecuadorian pilot has noticed a volcanic ash cloud above Tungurahua volcano, Ecuador

NOAA SO2 satellite imagery reveals ash clouds in the vicinity of Bagana volcano (PNG),  Ambrym (Vanuatu) and Mount Pagan (Mariana Islands)

Interesting articles
Submarine eruption generates pumice floaters at Mt. Monowai ? volcano (Kermadec Islands)
New Zealand scientists are investigating an undersea volcanic eruption which has created a large “pumice raft” 400km west of Raoul Island. GNS Science vulcanologist Craig Miller told NZ Newswire that the Royal New Zealand Air Force has provided photographs of the pumice raft and New Zealand’s National Maritime Coordination Centre has reported a sea disturbance 100 nautical miles long and 25 nautical miles wide, located 400km west of Raoul Island. Read more …
Update : other reports are mentioning that it can’t possibly be Monowai volcano as the pumice has been found away from this volcano.

Video
Pumice in the Kermadecs. An area of floating pumice 250 nautical miles in length and 30 nautical miles wide was spotted in the South Pacific ocean yesterday by a Royal New Zealand Air Force (RNZAF) Orion.

zTime goes here