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British Geological Survey brings maps, images and more to the web for free 7 December 2009

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Carsaig Arches, Mull. Volcanic rocks. Taken by Valentine & Sons, 1892. (NERC)

The British Geological Survey has brought a huge range of British geological data to the web for free at its new OpenGeoscience site. The site offers data, educational material, maps, pictures, reports and software free of charge for non-commercial private study, research and educational purposes. Among the resources available are tens of thousands of images via GeoScenic from the UK national geological photographic archive (of great historical as well as scientific interest), and map tools that integrate with Google Maps and Google Earth to show the geology underlying British streets, houses and feet.

Hypocentre has a detailed review of OpenGeoscience here.

Image: Carsaig Arches on the Isle of Mull. Lots of lovely volcanic rocks. Photograph taken by Valentine & Sons in 1892. From GeoScenic, courtesy British Geological Survey. Catalogue reference P232614.

News
British geology maps now free to explore on website – BBC News, 7 December 2009
In pictures: British geology – BBC News, 7 December 2009

Information
OpenGeoscience – geoscience data for free from the British Geological Survey
British Geological Survey – British Geological Survey website
National Environment Research Council – website for the NERC, of which the BGS is a part

The Volcanism Blog

Ocean crust formation not such a passive business 27 November 2009

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New research indicates that the formation of ocean crust is not always a passive business, but has an important dynamic component. The study is based on analysis of seismic wave velocities in the uppermost 200 km of the mantle beneath the Gulf of California:

The seismic waves in three localized centers, spaced about 250 kilometers (155 miles) apart, traveled more slowly than waves in the surrounding mantle, implying the presence of more melt in the localized centers and thus a more vigorous upwelling. From that, the geologists determined the centers, located 40-90 kilometers (25 to 56 miles) below the surface, showed evidence of dynamic upwelling in the mantle. [from the Brown University press release]

This research is published in a letter to the current issue of Nature (home of the snappy science headline – ‘Developmental Biology: Down the tube’, ‘Meteorology: Can’t beat the heat’, etc.), available in full to subscribers.

  • Yun Wang, Donald W. Forsyth & Brian Savage, ‘Convective upwelling in the mantle beneath the Gulf of California’, Nature, vol. 462 no. 7272 (26 Nov 2009), pp. 499-501 [doi:10.1038/nature08552]. Click here for summary.

Oceanic crust formation is dynamic after all – Brown University press release, 23 November 2009

The Volcanism Blog

Vast magma chamber lurking beneath Cascades? 25 October 2009

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It’s a racing certainty that before we can say ‘supervolcano obsession’ the Discovery Channel will be all over this:

A vast pool of molten rock in the continental crust that underlies southwestern Washington state could supply magma to three active volcanoes in the Cascade Mountains Mount St. Helens, Mount Rainier and Mount Adams according to a new study that’s causing a stir among scientists. The study, published Sunday in the magazine Nature Geoscience, concluded that the magma pool among the three mountains could be the ‘most widespread magma-bearing area of continental crust discovered so far’.

This theory is controversial, not least because it is based solely on magneto-telluric studies: seismic data on the area gives no support whatever to the suggestion that there is a ‘vast pool of molten rock’ down there. Anyway, Dr Erik Klemetti has everything you need to know about this over at Eruptions: ‘The return of the dreaded “giant magma chamber” of the Cascades’. He’s unconvinced, it’s fair to say.

News
Controversial study suggests vast magma pool under Washington state – 5NEWSonline.com, 25 October 2009

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More on climate change and volcanism from ‘Nature’ 18 September 2009

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The possible connection between climate change and increased volcanism has been attracting some attention recently. Now Nature takes a look at the issue in a news article headed ‘Volcanoes stirred by climate change‘: the point being that a reduction in ice cover may be related to more explosive eruptive activity from volcanoes (or, as Nature calls them, ‘these unstable magmatic beasts’).

Volcanoes stirred by climate changeNature, 17 September 2009

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Climate change: scientists warn of tectonic-volcanic geo-apocalyptic mega-mayhem 6 September 2009

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John Martin, 'The Great Day of His Wrath' (1853)
Above: John Martin’s ‘The Great Day of His Wrath’ (1853). An understatement, if anything.

University College London will be hosting a colloquium on ‘Climate Forcing of Geological Hazards’ from 15-17 September, which ‘will address relationships between past and contemporary climate change and the triggering of hazardous geological and geomorphological phenomena’. We’re looking at a future of earthquakes, avalanches, tsunamis, collapsing mountains and more volcanic eruptions, apparently. The Guardian has a report on the event today, under the headline ‘Global warming threatens Earth with wave of natural disasters’:

Melting glaciers will set off avalanches, floods and mud flows in the Alps and other mountain ranges; torrential rainfall in the UK is likely to cause widespread erosion; while disappearing Greenland and Antarctic ice sheets threaten to let loose underwater landslides, triggering tsunamis that could even strike the seas around Britain. At the same time the disappearance of ice caps will change the pressures acting on the Earth’s crust and set off volcanic eruptions across the globe.

The report quotes the reliably apocalyptic head of UCL’s Benfield Hazard Research Centre, Professor Bill McGuire: ‘Not only are the oceans and atmosphere conspiring against us, bringing baking temperatures, more powerful storms and floods, but the crust beneath our feet seems likely to join in too’.

The Volcanism Blog

Volcanoes take a holiday, glaciers rule the world 14 May 2009

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Around 2.4 billion years ago plate tectonics shut down, volcanism took a break for 250 million years, and glaciers spread across the world’s surface, it says here.

Volcano ‘vacation’ produced first glaciers – Discovery News, 14 May 2009

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Volcano research miscellany 7 May 2009

Posted by admin in Africa, current research, geoscience, Hawaii, Kilauea, Ol Doinyo Lengai, Pacific, submarine volcanism, Tanzania, United States.
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Various interesting bits and pieces of volcano-related research to report. Apologies for the lack of detail, but I’m pressed for time right now.

Ash evidence suggests impact of past eruptions underrated – a research team from the University of Oxford has studied the distribution of ash from the Chaitén eruption and concluded that the impact of past volcanic eruptions is likely to have been significantly underestimated, because so much ashfall is light (a few millimetres thickness) and is quickly lost from the areas affected. More on this at Science Daily, under the snappy headline Chaitén Volcano In Southern Chile: Historic Volcanic Eruptions Significantly Underestimated, Ash Fallout Analysis Shows.

Origins of Ol Doinyo Lengai’s weird lavas probed – the unique carbonatite lavas of Ol Doinyo Lengai volcano in Tanzania are produced by a very low degree of partial melting of the upper mantle minerals, concludes research to be published shortly in Nature by U.S. and French scientists. Science magazine’s ScienceNOW (caps lock stuck down?) news service also has an article on this, bafflingly entitled Volcanic Fish Out of Water.

Thriving ecosystem supported by NW-Rota 1 – scientists who have just returned from filming and studying the deep undersea volcano NW-Rota 1 report that the active volcano nourishes a rich and thriving biological community including shrimps, crabs, limpets and barnacles, some of which are new species. National Geographic News has some pictures.

Gentle, easy-going Kilauea has a dangerous side – between 1000 and 1600 years ago Kilauea, known today for its gentle tourist-friendly lava flows, chucked rocks 16 or 17 kilometres during powerful explosive eruptions.

The Volcanism Blog

Volcanoes’ jet-like roar 17 March 2009

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Infrasonic recordings of volcanic eruptions, when accelerated to bring the frequencies within the range of human hearing, reveal similarity to the noises made by jet engines, say the authors of a paper in Geophysical Research Letters. Such recordings could offer a new way of understanding what is going on in volcanic eruption columns, it says here.

  • R. S. Matoza, D. Fee, M. A. Garces, J. M. Seiner, P. A. Ramon, & M. A. H. Hedlin (2009), ‘Infrasonic jet noise from volcanic eruptions’, Geophysical Research Letters, in press [doi:10.1029/2008GL036486]. Link to PDF, subscribers only.

News
Volcanic roar may reveal jet physics at workNew Scientist, 16 March 2009

The Volcanism Blog

Is Nyiragongo atop a growing mantle plume? 13 March 2009

Posted by admin in Africa, Congo (Dem. Rep.), current research, geoscience, Nyiragongo, volcanology.
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The highly fluid, fast-moving lava produced by Nyiragongo volcano in the Democratic Republic of the Congo presents a dangerous volcanic hazard. In January 2002 the volcano erupted 14–34 × 106 m3 of lava from vents on its southern flanks, engulfing thousands of buildings in the nearby city of Goma and surrounding villages, killing about 50 people and leaving 120,000 people homeless. Twenty-five years earlier, in January 1977, a large death toll – possibly in the hundreds, and thought by some to be in the thousands – resulted from a similar eruption which produced lava flows with peak speeds estimated at 100km/h.

So what makes Nyiragongo’s lava unique? New research by Asish Basu of the University of Rochester (and others), published in Chemical Geology, suggests that a mantle plume is emerging beneath the volcano, feeding it with magma from a very deep source:

‘This is the most fluid lava anyone has seen in the world … It’s unlike anything coming out of any other volcano. We believe we’re seeing the beginning of a plume that is pushing up the entire area and contributing to volcanism and earthquakes.’

Basu analyzed the lava, which resides in the world’s largest lava lake—more than 600 feet wide inside the summit of Nyiragongo—and found that the isotopic compositions of neodymium and strontium are identical to ancient asteroids. This suggests, says Basu, that the lava is coming from a place deep inside the Earth where the source of molten rock is in its pristine condition.

For more details, see the press release from the University of Rochester. The paper itself is available to subscribers or to purchase via ScienceDirect:

  • Ramananda Chakrabarti, Asish R. Basu, Alba P. Santo, Dario Tedesco & Orlando Vaselli, ‘Isotopic and geochemical evidence for a heterogeneous mantle plume origin of the Virunga volcanics, Western rift, East African Rift system’, Chemical Geology, vol. 259, issues 3-4 (25 February 2009, pp. 273-289 [doi:10.1016/j.chemgeo.2008.11.010]

The Volcanism Blog

New sulphur dioxide monitoring methods – improving volcano and climate monitoring 13 March 2009

Posted by admin in climate, current research, geoscience, natural hazards, volcano monitoring, volcanology.
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A press release from the Swedish Research Council reports the work of Matthias Johansson, doctoral student in the Department of Radio and Space Science at Chalmers University in Göteborg, who has developed a system of measuring sulphur dioxide output from volcanoes by aggregating measurements taken from two or more instruments. Much of the work on the project ‘has involved making the equipment sufficiently automatic, robust, and energy-efficient for use in the inhospitable environment surrounding volcanoes, in poor countries with weak infrastructure’. The equipment is currently in use at seventeen locations.

The research also has implications for improved global climate monitoring by providing continuous measurements of the levels of sulphur dioxide emitted into the atmosphere by the world’s most active volcanoes:

‘Sulfur dioxide is converted in the atmosphere to sulfate particles, and these particles need to be factored into climate models if those models are to be accurate’, says Associate Professor Bo Galle, who directed [Johansson's] dissertation. Volcanoes are an extremely important source of sulfur dioxide. Aetna alone, for instance, releases roughly ten times more sulfur dioxide than all of Sweden does.’

The Chalmers research is part of Project Novac, a European Union funded project to establish networks for the measurements of volcanic gases and aerosols, and apply the data obtained to risk analysis and volcanological research, locally and on a regional and global scale.

UPDATE: I missed Ole Nielsen’s post of yesterday on this, at Olelog – Volcanic Eruption Forecasting.

The Volcanism Blog

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