Volcano activity of December 17, 2012 - Too much to summarise in a title

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. -

December 17, 2012 volcano activity

It just so happens that the OMI-SO2 satellite data show a small anomaly over Lokon today.
Mount Lokon erupted a little earlier today. People living near the volcano were surprised by a loud bang at 12:12 PM local time. The explosion was followed by hot ash-rich eruption clouds climbing to a height of 9000 fr or 3000 meters.
The volcano is in “standby or Siaga” status (second highest alert) since many months as the feeder basis remains open to fuel new eruptions. Ni special precautions have been taken at the moment. Since longer time, there is a 2.5 km NO-GO zone around the crater.
Tomohon a nearby village escaped merely to the ash fall today because of a favourable wind direction.
The image below is the VAAC (Volcanic Ash Advisory) map as reported by VAAC for 13:30 UTC . Ash concentrations are alerted up to 10,000 ft. Air traffic is requested to respect the alerts given by VAAC.
The volcano is active since a longer time, but eruptions like today’s are only happening now and then.


Tungurahua volcano (Ecuador) remains in full vulcanian eruption complete with ashfall, loud roars, pyroclastic flows,...the works! It's no surprise that Tungurahua seismograms are saturated with eruption tremor again today (station RETU). Plumes of volcanic ash have risen to over 7 km at times.

Eruption tremor at Plosky Tolbachik (Kamchatka Peninsula) has diminished only slightly overnight (signifying a continued high lava production rate). KVERT reports that the tremor eminating from Tolbachik continues to overwhelm seismometers at other nearby volcanoes including Klyuchevskoi and Bezymianny. The eruption plume at Plosky Tolbachik rises to around 3 km height again today.

Exhalations of gas and some ash continue to occur at an average rate of 3 per hour at Popocatepetl volcano (Mexico). The Popo seismogram shows low level volcanic tremor and some "chugging" earthquakes (likely associated with an exhalation).

Numerous small volcanic earthquakes and occasional pulses of volcanic tremor affect Pacaya volcano (Guatemala) (station PCG) again today. Things appear rather tranquil at the nearby cones of Fuego (station FG3) and Santa Maria (station STG6) volcanoes, with diminished levels of tremor at both. The "spikey" nature of the Santa Maria seismogram is due to malfunctioning seismographic, not the volcano.

Yet another "felt" earthquake at Machin volcano (Colombia) (station CIMA) today. The M3.7 earthquake eminated from 12 km deep within the southeast "nest" of seismicity beneath the volcano. Small earthquakes continue. Two days ago, a M3.2 event occurred at 15 km deep in the same area. Elsewhere in Colombia, a small ash emission occurred from Galeras volcano (the tremor signal on station ANGV) this morning.

Volcano-seismicity at Reventador volcano (Ecuador) has eased alittle the past few days (station CONE). The attached photo shows the relatively low level of surface activity associated with a rather high level of internal activity at the volcano.

Numerous small earthquakes dot seismograms at both Tongariro and Ruapehu (New Zealand) volcanoes, and volcanic tremor remains slightly elevated at White Island volcano where a small (growing?) lava dome was identified last week.

Pronounced SO2-enriched plumes were detected by satellite imagery at Ambrym (Vanuatu) and Nyiragongo (DRC) volcanoes. Lesser anomalies were spotted over Turrialba (Costa Rica) and Lokon (Sangihe Arc) volcanoes