Volcano activity of July 17, 2012 - Iliamna, Ambrym, Oregon cascades, Yellowstone, Popocatepetl, Fuego, Batu Tara, Nevado del Ruiz, Galeras and Sakurajima

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. -

July 17, 2012 volcano activity

While seismicity remains low, El Hierro continues to produce an occasional M3.0+ earthquake to keep everyone on their toes! Today a magnitude M3.4 struck the volcanic island.

In Alaska, Iliamna volcano showed some life today, firing-off three locatable earthquakes between M1.0 and M2.0.

The series of small earthquakes in the central Oregon Cascades that began at the first of this month continued with another small event early today. The cluster is in an area of young normal faults and volcanoes.

Seismicity has picked-up over the resurgent domes at Yellowstone the past few days. While nothing to be alarmed about, seismicity of this type (spasmodic tremor) has been very infrequent at the volcano since the big earthquake swarms in 2008-2209 and 2009-2010. (station YML from 12 JUly).

Volcano-tectonic seismicity is high again at Popocatepetl (Mexico) and emission of gas with some ash has increased to an average of over three times per hour during the past 24 hours.

It appears that Fuego (Guatemala) experienced some increased eruptive activity today as well. (station FG3)

Tremor remains low at Nevado Del Ruiz (Colombia) but SO2 emission is still strong enough to be visible to satellite sensors.

At nearby Galeras volcano (Colombia), short pulses of tremor are visible on seismograms. (station CUVZ)

Vanuatu's Ambrym volcano showed an increased SO2 plume on the satellite pictures earlier today

Activity observed by satellites

An eruption at 04:23 UTC showed an ash and gas cloud at a height of 7000 ft (2.1 km) at Sakurajima volcano, Japan's most active volcano of the moment

Featured volcanoes

In our Featured volcanoes series we published today currently active Batu Tara volcano at the Lesser Sunda Islands in Indonesia