Dr Erik Klemetti is in The Reef Tank 13 July 2009Posted by admin in blogs, geoblogosphere, volcanology.
The Reef Tank is a bulletin-board (although there’s much more to it than that term implies) for aquarists to discuss matters aquatic. They take an admirably broad view of their subject area, and have published a great interview with Dr Erik Klemetti of the Eruptions blog in which marine connections with volcanism are expertly dissected. Dr Klemetti also talks about his inspiration in setting up Eruptions (and has some nice things to say about The Volcanism Blog in passing).
- Point of eruption – The Reef Tank, 10 July 2009
Undersea explosive eruptions named ‘neptunian’ 5 July 2009Posted by admin in current research, geoscience, volcanology.
Tags: neptunian, submarine volcanism, undersea volcanism, volcanological research
Two researchers from the School of Earth Sciences and Centre of Excellence in Ore Deposits (CODES) at the University of Tasmania have come up with the name ‘neptunian’ to describe undersea explosive volcanic eruptions, says a report at ScienceDaily.
These eruptions are sustained and driven by gas exsolved from magma … Neptunian eruptions differ dramatically from magmatic-gas-driven explosive eruptions on land, reflecting the important influence of confining pressure and the higher heat capacity, density, and viscosity of water compared to air.
The original article (abstract here) by Sharon R. Allen and Jocelyn McPhie of CODES can be found in Geology: Sharon R. Allen and Jocelyn McPhie, ‘Products of neptunian eruptions’, Geology, July 2009, pp. 639-642 [DOI 10.1130/G30007A.1].
N.B. Not to be confused with Neptunism.
Tags: volcanology, Soufrière Hills, volcano research, Natural Environment Research Council, NERC, British Geological Survey
The Natural Environment Research Council ‘is the UK’s main agency for funding and managing research, training and knowledge exchange in the environmental sciences’ (says the NERC ‘what we do’ page). The NERC is responsible for the British Antarctic Survey and the British Geological Survey, among many many other things, and has a strong commitment to natural hazards research, including (of course) volcanoes. To give a notable current example of the NERC’s involvement in this field, it provided emergency funding for the recent important studies of ashfall at Chaitén carried out by a University of Oxford research team.
All this is by way of background, and to point out that if you’re interested in volcanological and natural hazards research, the NERC is an agency to watch. Today there’s a new podcast available on the NERC’s Planet Earth Online environmental news service: ‘Watching volcanoes’. In the podcast (duration 6 min 42 sec) Richard Hollingham talks to Dr Sue Loughlin and Dr Kathryn Goodenough of the British Geological Survey about how studying currently active volcanoes (Montserrat) and the remains of ancient volcanoes (Edinburgh) informs our knowledge of volcanic processes and improves our ability to forecast future volcanic behaviour. It’s a model of clear exposition and an excellent example of scientific outreach.
The Planet Earth podcast – ‘Watching volcanoes’ (18 May 2009)
BBC documentary probes the volcanoes of Danakil 19 March 2009Posted by admin in Africa, Erta Ale, Ethiopia, volcanology.
Tags: BBC, Danakil, Erta Ale, Ethiopia, volcanology
There’s only one thing that is more important than news on the BBC News website, and that’s self-promotion: hence the thinly-disguised plugs for BBC television and radio programmes that regularly infest the BBC News pages. Just occasionally, however, the BBC self-publicity machine throws up something worthwhile.
A new two-part documentary on the Danakil region of north-eastern Ethiopia, Hottest Place on Earth, will (among other things) look at the fascinating geology of the region. As part of the programme Dr Dougal Jerram of Durham University will be using 3D technology to provide high resolution maps of the interior of the Dabbahu fissure and the crater of Erta Ale volcano. BBC News has an interesting article by Dr Jerram in which he tells us all about it. The video extract showing his descent into Erta Ale is fascinating, and visually stunning.
The Danakil region was the setting for last November’s dramatic fissure eruption at Alu/Dalaffilla. It would be really nice if some enterprising scientific documentary maker went there and had a look around.
(The BBC likes to get its geologist-presenters to abseil into Erta Ale whenever possible. It’s not that long ago that Dr Iain Stewart was doing it for Earth: Power of the Planet. The video of that found its way onto the BBC News website as well.)
Volcanoes’ jet-like roar 17 March 2009Posted by admin in current research, geoscience, volcanology.
Tags: geophysics, geoscience, volcano research, volcanology
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.
Volcanic roar may reveal jet physics at work – New Scientist, 16 March 2009
Is Nyiragongo atop a growing mantle plume? 13 March 2009Posted by admin in Africa, Congo (Dem. Rep.), current research, geoscience, Nyiragongo, volcanology.
Tags: Africa, geoscience, mantle plumes, Nyiragongo, volcano research
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]
Tags: geoscience, natural hazards, volcano monitoring, volcano research, volcanology
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.
Olympus Mons, lopsided giant 11 February 2009Posted by admin in current research, geoscience, Mars, solar system, volcanology.
Tags: Mars, Olympus Mons, solar system volcanism
Olympus Mons, the largest mountain and the largest volcano we know of in the Solar System, is a huge shield volcano on Mars. It rises 23km above the Martian plain, is approximately 600km in diameter, and is lopsided, like a vast unsuccessful cake. The gently-sloping north-west flank of the volcano extends much further from the central caldera complex than does the steeply-sloping south-eastern flank; these flanks are also upwardly concave, showing an overall increase in the steepness of slope towards the centre, and are divided from the surrounding terrain by steep scarps, features not found in other sectors. A new paper on Olympus Mons in the February 2009 issue of Geology looks at the possible reasons for what it calls these ‘substantial asymmetries in its structure’. From the abstract:
The NW-SE asymmetries are aligned with the regional slope from the Tharsis rise, but an understanding of the underlying causes has remained elusive. We use particle dynamics models of growing, spreading volcanoes to demonstrate that these flank structures could reflect the properties of the basement materials underlying Olympus Mons. We find that basal slopes alone are insufficient to produce the observed concave-upward slopes and asymmetries in flank extent and deformation style that are observed at Olympus Mons; instead, lateral variations in basal friction are required. These variations are most likely related to the presence of sediments, transported and preferentially accumulated downslope from the Tharsis rise. Such sediments likely correspond to ancient phyllosilicates (clays) recently discovered by the Mars Express mission.
Thus the north-west flank of the edifice spreads more easily across the thickened sediments downhill from the Tharsis rise, while the south-east flank encounters the high-friction zone of the elevated pre-sediment basement which inhibits its spread. Result: a lopsided volcano. The sediments beneath forming the low-friction basal zone beneath Olympus Mons would need to be good at retaining water, making clays the obvious candidates, and the authors note that the spectral signatures of clay materials have been detected by the Mars Express OMEGA imaging spectrometer.
In the last, four-sentence, paragraph of the paper the authors suggest that ‘[these] results have implications for extant life on Mars’. The erupted lavas of Olympus Mons could have trapped a water reservoir in the sediments beneath: ‘This deep reservoir, warmed by geothermal gradients and magmatic heat and protected from adverse surface conditions, would be a favored environment for the development and maintenance of thermophilic organisms’. Hence the headline at Australia’s ABC Science today: ‘Martian volcano could shelter life’.
- Patrick K. McGovern & Julia K. Morgan, ‘Volcanic spreading and lateral variations in the structure of Olympus Mons, Mars’, Geology, vol. 37, no. 2 (February 2009), pp. 139-142. [Link to abstract only]
Image: mosaic of Olympus Mons created with the medium-resolution black and white MDIM combined with a low resolution color image mosaic acquired on the 735 orbit of Viking 1 on 22 June 1978. Image Processing by Jody Swann/Tammy Becker/Alfred McEwen, using the PICS (Planetary Image Cartography System) image processing system developed at the U.S. Geological Survey in Flagstaff, Arizona (NASA/NSSDC image).
Volcanic spreading and lateral variations in structure of Olympus Mons, Mars – ScienceDaily, 3 February 2009
Martian volcano could shelter life – ABC Science, 11 February 2009
ESA – Mars Express – home page for the ESA Mars Express mission
Unravelling part of Olympus Mons’ geologic history – HiRISE High Resolution Imaging Science Experiment (University of Arizona)
Volcanic Geology of Mars – from Albert T. Hsui, University of Illinois (Urbana-Champaign)
Highest and lowest points on Mars – Geology.com (on Olympus Mons and the Hellas Impact Crater)
Olympus Mons – Mike Dunford at The Questionable Authority shows just how big Olympus Mons is
Chile establishes permanent co-ordination system for seismic and volcanic monitoring 4 February 2009Posted by admin in Chaitén, Chile, natural hazards, volcano monitoring, volcanology.
Tags: Chaitén, Chile, natural hazards, South America, volcano monitoring, volcanology
Among the consequences of the Chaitén eruption has been renewed attention in Chile to the question of volcanic hazard monitoring and communication. Volcano monitoring in Chile is the responsibility of the Servicio Nacional de Geología y Minería (SERNAGEOMIN). Seven Chilean volcanoes are currently monitored on a permanent basis: Lonquimay, Llaima, Villarrica, Mocho-Choshuenco, Osorno, Calbuco, and (since it erupted) Chaitén. Chile has one volcanological observatory, the Observatorio Volcanológico de los Andes del Sur (OVDAS), located in the central-southern city of Temuco and operated by SERNAGEOMIN.
The Chaitén eruption has highlighted some long-standing and long-disregarded problems with volcano monitoring in Chile: lack of finance, staffing and infrastructure, inadequate volcanic hazard research, poor co-ordination and co-operation between the responsible authorities, poor public communication. Since last year, however, there has been a new drive to improve things from within the Chilean government and parliament, and with assistance from the United States Geological Service through the Volcano Disaster Assistance Program the situation is changing for the better. It is to be hoped that the impetus will be maintained.
On 28 January 2009 the President of Chile, Michele Bachelet, signed a decree establishing a Sistema de Coordinación Permanente de Procesos de Monitoreo Sísmico y Volcánico, a ‘Permanent Co-ordination System for Seismic and Volcanic Monitoring’. The President described this as ‘one more step in the institutional strengthening of the management of natural hazards’ in Chile, alongside the development of relevant scientific knowledge and skills, hazard research and the better dissemination of information. The next step is a draft law, to be put before parliament in March, to transform the present Oficina Nacional de Emergencia (ONEMI) into a more capable Dirección Nacional de Protección Civil, National Civil Protection Directorate, ‘with greater capacities and co-ordinated facilities for responding to disasters’. It seems that the intention is to make this beefed-up ONEMI, freed from the control of the Ministry of the Interior, into the lead state agency for emergency response.
ONEMI has the lead role at present in the development of the co-ordinated seismic and volcanic monitoring system established by this decree, bringing together the capabilities and operations of ONEMI’s own scientists, SERNAGEOMIN, the Chilean universities, and the Chilean Navy’s hydrographic and oceanographic services. SERNAGEOMIN and the Red Sismológica Nacional (National Seismological Network) are to be enlarged and developed to improve their volcanic and seismic monitoring and research capabilities.
These measures, which form part of the Chile Bicentenario project to enhance and develop many aspects of Chile’s national life in preparation for the bicentenary of the country’s independence in 2010, are all very encouraging. The Volcanism Blog will continue to monitor developments in Chile.
Bachelet firmó decreto para coordinar monitoreo de sismos y volcanes – Radio Cooperativa, 28 January 2009
Gobierno prepara proyecto de ley para entregar mayores recursos e independencia a la Onemi – La Tercera, 28 January 2009
Bachelet firmó decreto que establece sistema permanente de monitoreo sísmico y volcánico – Terra Chile, 28 January 2009
Decreto establece monitoreo de actividad sísmica y volcánica – 123 Chile, 28 January 2009
Chaitén update at the Eruptions blog 25 January 2009Posted by admin in Chaitén, Chile, eruptions, geoscience, volcanology.
Tags: Chaitén, Chile, geoscience, South America, volcanic eruptions, volcanology
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.