Volcano activity of August 16-17, 2012 - Ivan Groznyy, Monowai seamount, Mt. Semeru, Soufriere Hills, El Hierro, Tungurahua, White Island, Mt. Tongariro and Batu Tara

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 16-17, 2012 volcano activity

The Ivan Groznyy (“Ivan the Terrible”) volcano erupted early on Thursday morning on the island of Iturup, part of the Kuril group in Russia's Far East. The volcano spewed a column of ash onto the surrounding area. Local people in the nearest towns, Goryachiye Klyuchi (9 kilometers away) and the city of Kurilsk (25 kilometers), noticed a faint smell of hydrogen sulfide gas, which disappeared later.  The eruption poses no threat to nearby human settlements. Read more here ...  (Thanks to ER reader Kukide for telling us)

Image courtesy Smitsonian Institute - Photo by A. Korablev, 1993 (Institute of Marine Geology and Geophysics, Yuzhno-Sakhalin)

According to Institute of Geological & Nuclear Sciences Limited (GNS) in a media release on 11 August, the Laboratoire de Géophysique (Papeete, Tahiti) reported that seismographs in Rarotonga recorded eruptive activity at Monowai seamount on 3 August. The activity then stopped overnight.  See also the article we published on the massive amounts of pumice found in the greater Kermadec Islands area.

MVO reported that during 3-10 August activity at the Soufrière Hills (Montserrat) lava dome was mostly at a low level. The seismic network detected two small swarms of volcano-tectonic earthquakes on 7 and 8 August. Scientists at MVO observed a period of ash venting that began at 1700 on 8 August, less than two hours after the second swarm. Roaring sounds were heard at the same time. The ash plume drifted W over Plymouth at an altitude of about 1 km (3,280 ft) a.s.l., and a small amount of ashfall was reported by a fisherman offshore. The source of the venting appeared to be the gas vent in the floor of the 11 February 2010 collapse scar, and not the crater created on 23 March 2012.
On 9 August the inside of the collapse scar was partially visible during a helicopter flight. Fumarolic activity in the 23 March crater had increased compared to two weeks ago, and some other fumaroles were also more active. A change in wind direction shifted the volcanic plume N for much of the day and the odor of volcanic gas was noticeable in some inhabited areas. The Hazard Level remained at 2 (on a scale of 1-5).

El Hierro volcano (Spain) has awakened again by triggering a lot of weak volcanic earthquakes in the earlier eruption feeder El Golfo area. Seismicity is still at 10 to 12 km, but compared to the massive swarm which started at the end of june, bot location and depth are in a totally different area. In-depth reporting can be followed in our never-ending article here.

Alert levels at both New Zealand active volcanoes White Island and Mt. Tongariro have been decreased from 2 to 1. Further eruptions are not likely within a short term.

Tungurahua volcano in Ecuador continues to be active. Ash eruptions can often only be heard as a thick cloud cover blocks the view of the crater. The seismogram (RETU) shows what is going on.

Activity observed by satellites
VAAC Darwin continues to report volcanic ash above Batu Tara volcano, Indonesia

Interesting articles
United States Mint to Launch Hawai'i Volcanoes National Park Quarter
The U.S. Mint and the National Park Service next week will unveil a new quarter coin featuring the Hawaii Volcanoes National Park. The agencies plan to hold a ceremony near the Kilauea volcano on Wednesday to introduce the new coin, which is part of the Mint’s “America the Beautiful” quarters program that started in 2010 and which depicts 56 national parks and other national sites. Read more and watch an example ...

Video
Explorer & Adventurer George Kourounis climbs to the summit of Mount Semeru in East Java, Indonesia. Semeru is the highest peak on the island of Java and is an active volcano with several explosions each hour.