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Backyard lava from NOVA Geoblog 18 February 2009

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Every hot rocks fan should see the video that Callan Bentley has up at his NOVA Geoblog of the successful attempt by a friend and colleague of his to make lava in his backyard, using just two rock samples and an acetylene torch.

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Chaitén update at the Eruptions blog 25 January 2009

Posted by admin in Chaitén, Chile, eruptions, geoscience, volcanology.
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The Chaitén eruption has volcanologists and geologists everywhere excited, and was evidently the subject of much discussion at the American Geophysical Union Fall 2008 meeting in San Francisco.

Dr Erik Klemetti was there, and has posted a valuable update on his Eruptions blog summarizing what was said about Chaitén at the meeting and giving copious links to the relevant abstracts and other sources. Among the interesting points to note are that we seem to be looking at a very deep source for Chaitén’s magma and that earthquakes may have played a role in instigating the eruption. Check out Dr Klemetti’s post for the background.

There’s no doubt that Chaitén is going to be keeping the scientists busy for a long time to come.

Chaitén coverage here at The Volcanism Blog: Chaitén « The Volcanism Blog.
Chaitén coverage at Eruptions: Chaiten « Eruptions.

The Volcanism Blog

New pyroclastic flow mapping tool 23 January 2009

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When it comes to responding to a dangerous volcanic eruption, time can be very short indeed. Volcanologists and civil defence/emergency services personnel need the best information possible, as quickly as possible, if hazards are to be understood and lives saved.

That’s what makes a new advance reported by Andrew Alden at his geology blog today very interesting and important. Scientists at Penn State University and the USGS Cascades Volcano Observatory have taken a program used to predict the paths and volumes of lahars and adapted it to do the same trick for pyroclastic flows. The introduction to their research article, ‘Objective rapid delineation of areas at risk from block-and-ash pyroclastic flows and surges’, in the Bulletin of Volcanology (link is to abstract only) observes:

Pyroclastic flows and surges are arguably the most severe hazards from volcanoes … In many volcanic crises a hazard map for pyroclastic flows and surges is sorely needed, but limited time, exposures, or safety aspects may preclude field work, and insufficient computational time or baseline data may be available for adequately reliable dynamic simulations of future pyroclastic flow or surge events.

A press release from Penn State provides an example of the kind of hazard map this program can provide, in this case of potential pyroclastic flow paths at Soufrière Hills volcano in Montserrat:

This is a map of the Soufriere Hills Volcano, Montserrat, indicating the potential hazards given differing volumes of material in the pyroclastic flow
Above: This is a map of the Soufriere Hills Volcano, Montserrat, indicating the potential hazards given differing volumes of material in the pyroclastic flow. (Credit: Barry Voight, Christina Widiwijiyanti; Penn State. Source.)

The colours indicate the areas likely to be inundated by pyroclastic flows with volumes ranging from 1 million cubic metres (red) to 6.8 million cubic metres (blue). Such maps can be produced very quickly and made available to people on the ground at the site of a volcanic eruption. As Andrew Alden observes, ‘A map is invaluable in planning evacuations—and convincing in getting people to move’.

The Volcanism Blog

Volcano geodesy at Green Gabbro 9 January 2009

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Over at Green Gabbro, Maria Brumm has posted a crystal-clear explanation of the use of GPS networks to measure surface change, which can be an important indicator of volcanic activity. Great cartoon, among other things.

Green Gabbro: Volcano Geodesy 101

The Volcanism Blog

Checking out the Soufrière Hills magma sponge 22 December 2008

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Why does the active Soufrière Hills volcano on the British Caribbean island of Montserrat produce far more lava than anyone would expect from the degree of surface deformation it shows? Because it’s fed by a magma sponge, says Barry Voight, professor emeritus of geosciences at Penn State:

‘The magma volume in Montserrat eruptions is much larger than anyone would estimate from the surface deformation, because of the elastic storage of magma in what is effectively a huge magma sponge’, says Voight. ‘Magma is continually fed into the chamber from below at a rate of about two cubic meters per second — about the volume of a large refrigerator every second’.

The magma in the chamber below Soufrière Hills is rich in water, carbon dioxide and sulphur dioxide and is very compressible, making for elastic magma storage. This is one of the discoveries of the ongoing CALIPSO project to image Soufrière Hills using GPS and seismic remote sensing techniques similar to those of a medical CAT scan. The CALIPSO team has been reporting on its findings at the AGU Fall Meeting: read all about it at EurekAlert.

The Volcanism Blog

Whoops, magma 17 December 2008

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Drillers working for a geothermal energy company in Hawaii got very geothermal when they drilled right into a magma chamber, reports the BBC today. Apparently a crew working for Puna Geothermal Venture was putting an exploratory well into eastern Big Island, through Kilauea’s lava fields, when they unexpectedly hit hot rock at a shallow 2.5km. The stuff ascended the bore but cooled and solidified a few metres up, before a world-engulfing Hollywood-style catastrophe could occur. This happened in 2005, but the event is only just now being reported at the AGU Fall Meeting in San Francisco.

This discovery allows geologists to look at magma in its ‘natural habitat’, says Professor Bruce Marsh of Johns Hopkins University:

‘Before, all we had to deal with were lava flows; but they are the end of a magma’s life. They’re lying there on the surface, they’ve de-gassed. It’s not the natural habitat. It’s the difference between looking at dinosaur bones in a museum and seeing a real, living dinosaur roaming out in the field.’

The material in the magma chamber is slowly cooling, providing an opportunity for scientists to study the processes of differentiation that occur as magma solidifies into continent-forming rock: ‘it could be this is how continents could have been started to be built on the planet’, says Prof Marsh in an interestingly-formed sentence.

‘Don’t these people look where they are drilling?’ asks Chris Rowan at Highly Allochthonous.

The Volcanism Blog

Volcanic gas sampling by mini-helicopter 18 November 2008

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‘Model helicopter “predicts volcanoes”‘ is the surprising headline in a BBC News report today. A modern version of the old ‘animals predict earthquakes’ idea, perhaps? Well, no, it’s a reference to the work of Dr Andrew McGonigle, a University of Sheffield scientist who has won an international award worth £67,000 for his work on remote sampling of volcanic gases using a radio-controlled model helicopter. Thus, it’s the scientists who would be the ones doing the predicting, not the helicopter; and this isn’t so much ‘a new way to help predict when volcanoes will erupt’ (to quote another BBC News report) as a new way to gather the information which helps predict when volcanoes will erupt. In essence, Dr McGonigle’s instrumented helicopter is a highly developed, economical and very flexible remote monitoring system with great potential for improving scientists’ capability of predicting volcano behaviour and thus saving lives. The first helicopter is called Aerovolc I; the money from Rolex will go towards the development of Aerovolc II, which will be deployed at Etna and Stromboli.

Dr McGonigle’s page at the University of Sheffield, with information about his research into volcano remote sensing and much else, is here, and a profile of his project on the Rolex Awards website is here.

Congratulations to Dr McGonigle on his award.

News
Volcano scientist wins accolade – BBC News, 18 November 2008
Model helicopter ‘predicts volcanoes’ – BBC News, 18 November 2008
Award for city volcano scientist
Edinburgh Evening News, 18 November 2008
The remote-controlled helicopter that predicts volcanic eruptionsDiscover Magazine, 18 November 2008

The Volcanism Blog

Ethiopian eruption – further coverage 10 November 2008

Posted by admin in Africa, Alu, Dalaffilla, Erta Ale, eruptions, Ethiopia, geoscience.
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NASA’s Earth Observatory has a feature today on one of the MODIS images of the eruption in the Afar region of north-east Ethiopia, captured by NASA’s Aqua satellite on 4 November, that have been discussed here in an earlier post: Activity on the Erta Ale Range.

This link came via Geology.com, who also have a very useful article on the wider geological context for all that’s going on in the Ethiopian Rift: East Africa’s Great Rift Valley: A Complex Rift System (by James Wood and Alex Guth). For further background reading, try this article from Spiegel Online, March 2006: Africa’s New Ocean: A Continent Splits Apart.

Viewing the Ethiopia category will bring up previous posts from The Volcanism Blog on this eruption.

The Volcanism Blog

Simulating volcanic seismicity in the lab 10 October 2008

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Scientists from Britain, Canada and Italy have recreated the processes of deformation and fracture which affect the rock that makes up volcanoes inside the laboratory, monitoring and analyzing the stress signals produced when the rock reacts to pressure. The resulting data can be used to understand what is happening in full-size volcanoes, improving the accuracy with which volcanic seismicity can be analyzed and used to forecast eruptions. Reuters reports:

Active volcanoes produce a mix of seismic signals or small earthquakes that can indicate an eruption, but interpreting their significance is notoriously difficult. So the capacity to analyze these signals under laboratory conditions and understand how they are caused by water, steam, gas or magma rushing through cracks in rock is a significant step forward.

The rock used was basalt from Mount Etna. Water was forced through under pressure to simulate the conditions within an erupting volcano. The resulting report, ‘Laboratory simulation of volcanic seismicity’, can be found in the 10 October 2008 edition of Science (link is to abstract only, subscription required for full access).

News
Volcano in lab may help predict real eruptions – Reuters, 9 October 2008
Sounds of volcanic eruption recreated – MSNBC, 9 October 2008
Simulata in laboratorio l’eruzione di un vulcanoIl Messaggero, 9 October 2008 (Italian)

The Volcanism Blog

Soufrière Hills study reveals complex eruption processes 9 October 2008

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A new UK/US study of the Soufrière Hills volcano in Montserrat has revealed new levels of complexity in the processes that produce volcanic eruptions. Magma does not, it seems, ‘balloon’ at depth before forcing its way to the surface, but is released from a deeper magma chamber into a shallower reservoir through a ‘valve’ mechanism that opens and shuts. This interaction between the upper and lower reservoirs produces ‘pulses’ of magma, reports ScienceDaily, leading to irregular eruption patterns:

The pattern of eruptions and pauses might suggest that the magma beneath the Earth behaves in a stop-and-start pattern but the data indicate that magma production beneath the volcano is continuous and relatively constant. During eruptive pauses, the magma supply inflates the deep chamber until this stored magma is released into the upper chamber where it forces a renewed eruption. These observations implicate the deep reservoir in setting the timing of eruptions, rather than the shallow chamber, as had previously been considered.

The Soufrière Hills study involved scientists from the University of East Anglia, Penn State University and the University of Arkansas and is published in the 10 October 2008 issue of Science magazine: ‘Implications of magma transfer between multiple reservoirs on eruption recycling’ (link is to abstract only, subscription required for full access).

UPDATE: More on this at Erik Klemetti’s Eruptions blog: ‘A magma chamber’s ebb and flow’.

News
Volcanic eruptions more complex and harder to predict – ScienceDaily, 9 October 2008
Volcanic eruptions more complex and harder to predict, according to new Science paper – EurekAlert, 9 October 2008
Volcanoes ‘reload’ with magma, making them more difficult to predictDaily Telegraph, 9 October 2008

The Volcanism Blog