The volcano forecast: something a little different 5 March 2010
Posted by admin in miscellaneous.Tags: miscellaneous, podcasts. comedy, Shift Run Stop
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Here in the United Kingdom one of the enduring pillars of our national life is the Shipping Forecast, a report on weather conditions around British and Irish shores put together by the Met Office and H.M. Coastguard and broadcast four times a day on BBC Radio 4. It may seem rather utilitarian, but the forecast has a certain poetic and imaginative quality that gives it an appeal far beyond the maritime community for whom it is a vital service.
Reading the Shipping Forecast is among the jobs of the BBC Radio Four announcers, and one of their number, the mellifluously-voiced Zeb Soanes, is a guest on the latest edition (no. 16) of the Shift Run Stop podcast put together by Leila Johnston and Roo Reynolds. Leila, a big fan of the regular SI/USGS Weekly Volcanic Activity Reports featured on this blog (and who wouldn’t be?) suggested Zeb should read a ‘volcanic activity forecast’ in the style of the Shipping Forecast, so I lightly adapted the 10-16 February report for him to read. The result, although it most definitely should not be relied upon by anyone seeking information about volcanic activity, is quite superb: you’ve no idea of the comic potential inherent in the term ‘small pyroclastic flow moving northwards’ until you’ve heard Zeb reading it.
You can hear the volcanic activity forecast at Shift Run Stop by clicking here to access the podcast. The volcano bit starts at about 20 minutes in (although you really ought to hear the whole thing, and then subscribe and buy the tape).
Eyjafjallajökull and Katla: restless neighbours 4 March 2010
Posted by admin in activity reports, Eyjafjöll, Iceland.Tags: Eyjafjallajökull, Eyjafjöll, Iceland
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The Icelandic volcano Eyjafjallajökull has been very restless recently. The current seismicity and apparent inflation may be precursory to an eruption, or it may not – as Hugh Tuffen of Lancaster University observes, this kind of activity has been seen before, associated with dyke intrusion events (although the current seismicity is unusually energetic) and it is not possible at the moment to say whether this time it will end in an eruption: ‘time will tell’. An interesting detail about the current activity comes from a source in Iceland who tells me that magma degassing under Eyjafjallajökull produced an ‘acid pulse’ that led to local water supplies become temporarily acidic about a month ago.
Eyjafjallajökull is an interesting volcano, not least because of its relationship with its near neighbour, Katla. This much larger volcano lies less than 30 km to the east of Eyjafjallajökull, beneath the Myrdalsjökull icecap. Katla is, the Global Volcanism Program reports, ‘one of Iceland’s most active [volcanoes] and is a frequent producer of damaging jökulhlaups, or glacier-outburst floods’. Katla, with more than twenty confirmed eruptions since the sixth century AD, has a much more active eruptive history than Eyjafjallajökull, which has just three eruptions over the same period. It seems, however, that there is a connection between these two closely-spaced volcanoes. Eyjafjallajökull’s most recent eruption, December 1821 to January 1823, was followed by an eruption of Katla in June and July 1823. More recently an intrusion at Eyjafjallajökull in 1999 appears to have been followed by a small subglacial eruption in the Katla caldera.
It’s intriguing that recent earthquake activity around Katla and Eyjafjallajökull has clustered in three areas: (1) shallow quakes around and within the Eyjafjallajökull caldera, (2) shallow quakes largely confined to the eastern part of Katla caldera, and (3) quakes with a deeper focus in the Godabunga area between the first two clusters. One possible interpretation of this pattern is that a cryptodome – an underground lava dome – is active beneath this area. The presence of viscous rhyolitic lava beneath Katla and Eyjafjallajökull makes for potentially explosive eruptive activity, if an eruption occurs.
An Icelandic commenter at Eruptions reports that the Iceland Meteorological Office do not expect an eruption at Eyjafjallajökull. The volcano may get over its current bout of restlessness and calm down again, as happened with the intrusion events of 1994, 1999 and 2009. It clearly needs careful watching, however, as does its large and destructive neighbour, Katla.
[Grateful thanks for information received to 'a source at the Department of Geophysics, University Of Iceland'.]
SI/USGS Weekly Volcanic Activity Report 24 February-2 March 2010 4 March 2010
Posted by admin in activity reports, Caribbean, Costa Rica, Ecuador, eruptions, Fuego, Guatemala, Hawaii, Indonesia, Japan, Kamchatka, Karymsky, Kilauea, Kliuchevskoi, Mayon, Mexico, Pacaya, Philippines, Poás, Popocatépetl, Russia, Sakura-jima, Santa María, Semeru, Shiveluch, Soufrière Hills, Tungurahua, United States, Weekly Volcanic Activity Reports.Tags: Global Volcanism Program, volcanic activity reports, volcanic eruptions
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Some highlights from the last week of volcanic activity reported by the Global Volcanism Program:
- Poás: grey and sulphur-scented sediment thrown out by a phreatic explosion
- Santa María: ash plumes from the Santiaguito lava dome complex reached 2.8-3.1 km altitude
- Tungurahua: ash plumes reached 6.5-8.0 km altitude
Click on the map for a larger version (1280 x 898 pixels).
The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 24 February-2 March 2010 is now available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.
- The current report: Weekly Volcanic Activity Report.
- Previous reports: Weekly Reports Archive.
- The SI/USGS map of volcanoes discussed this week.
New activity/unrest: Poás (Costa Rica), Semeru (Indonesia), Soufrière Hills (Montserrat).
Ongoing activity: Fuego (Guatemala), Karymsky (Russia), Kilauea (USA), Kliuchevskoi (Russia), Mayon (Philippines), Pacaya (Guatemala), Popocatépetl (Mexico), Sakura-jima (Japan), Santa María (Guatemala), Shiveluch (Russia), Tungurahua (Ecuador).
Iceland: something happening under Eyjafjallajökull? 3 March 2010
Posted by admin in Eyjafjöll, Iceland.Tags: Eyjafjallajökull, Eyjafjöll, Iceland
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Eyjafjallajökull in southern Iceland is showing distinct signs of restlessness, with intensive seismic activity being recorded over the last 48 hours. The map above comes from the Iceland Meteorological Office page for earthquakes in the Mýrdalsjökull area, and shows the situation at 20:10 GMT this evening. Eyjafjallajökull, which last erupted in the early nineteenth century, is a glaciated stratovolcano adjacent to Katla volcano (with which it may be connected in some way, although chemically the lavas from the two volcanoes are quite different). A flurry of shallow seismic activity since the beginning of this year, and some inflation detected by GPS monitoring, appears to indicate that an intrusion of some kind is under way under Eyjafjallajökull.
[Thanks go to Boris Behncke for the tip about the current activity. I'm also very grateful to a generous and well-informed source in Iceland who has provided quite a lot of detailed information about Eyjafjallajökull which I hope to post tomorrow.]
UPDATE 4 March 2010. Hugh Tuffen of Lancaster University reports (comment below) that the earthquakes are becoming more frequent and shallower. He also observes that if an eruption occurs at Eyjafjallajökull there is a danger of jokulhlaups/lahars. And another UPDATE, Erik Klemetti has a very full post about Eyjafjallajökull over at Eruptions: Increasing signs of activity at Eyjafjallajökull in Iceland.
UPDATE 21 March 2010. It’s erupted: Eyjafjallajökull volcano erupts.
Information
Global Volcanism Program: Eyjafjöll – summary information for Eyjafjallajökull, which the GVP calls Eyjafjöll (1702-02=)
Chile tsunami: images of the aftermath 3 March 2010
Posted by admin in volcanoes.Tags: Chile, earthquakes, natural hazards, tsunamis
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The Chilean newspaper El Mercurio has published a series of dramatic high-definition aerial photographs of the devastation caused along Chile’s coast by the tsunami associated with the 27 February 2010 earthquake.
Fotos aéreas del terremoto en Chile – El Mercurio, 2 March 2010
[Thanks go to Guillermo for the link.]
New light on Mammoth Mountain and Long Valley Caldera 3 March 2010
Posted by admin in Long Valley, Mammoth Mountain, volcanoes.Tags: Long Valley Caldera, Mammoth Mountain, volcanological research
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New research (link to abstract) in the March 2010 issue of the Geological Society of America Bulletin sheds new light on the volcanism of the Long Valley caldera complex in eastern California, clarifying the eruptive sequence and the character of eruptive activity over the last 190,000 years.
Four eruptive sequences have been identified by Gail Mahood of Stanford University and her co-researchers, who used argon isotopes to study the lavas at Long Valley Caldera and Mammoth Mountain, which straddles the caldera’s south-west rim: the western moat sequence (~190,000–160,000 years ago), the Mammoth sequence (~120,000–58,000 years ago), the northwest caldera sequence (~41,000–29,000 years ago) and the Inyo chain sequence (from ~9,000 years ago to the present). This dating of the silicic lavas in the north-west sector of the caldera to ~41,000-29,000 years ago shows them to be rather younger than previously thought.
Interestingly, mafic and silicic lavas were produced simultaneously during the eruptions: ‘in each eruptive sequence mafic and silicic lavas erupted contemporaneously from spatially associated vents’. The authors suggest that if alkali basalt intruding into the crust caused the silicic eruptions, potentially small-volume silicic eruptions may be produced by this mechanism in future, producing explosive eruptions but within a limited area: they note that ‘In the past 40,000 years, eruptions have occurred along a N-S linear trend less than 10 km wide, limiting the zone subject to volcanic hazards’. This is useful information when it comes to planning for future eruptive activity. The eruption of basalt lava also indicates that no large magma body, which would absorb the basaltic material, is present below the caldera, Professor Mahood told the keen supervolcano fans at Discovery News.
The authors also note that their results provide ‘equivocal support for a suggested anticorrelation between volcanism and glaciation for the past 800,000 years in eastern California’ – that is, the theory that glaciation and volcanism alternated over that period, with maximum volcanism occurring during interglacial periods.
- Gail A. Mahood, Joshua H. Ring, Simone Manganelli & Michael O. McWilliams, ‘New 40Ar/39Ar ages reveal contemporaneous mafic and silicic eruptions during the past 160,000 years at Mammoth Mountain and Long Valley caldera, California’, Geological Society of America Bulletin, vol. 122, nos. 3-4 (March 2010), pp. 396-407. [doi: 10.1130/B26396.1]. Link to abstract.
News
California supervolcano has split personality – Discovery News, 2 March 2010
Information
Global Volcanism Program: Long Valley – information summary for Long Valley Caldera (120314-A)
Global Volcanism Program: Mammoth Mountain – information summary for Mammoth Mountain (1203-15-)
USGS Long Valley Observatory – website for the LVO, which keeps an eye on what the caldera is up to
Geological history of the Long Valley Caldera – from the LVO
Random rumblings: hydrothermal vents re-colonized from afar, Yellowstone swarm, Krakatoa, Mauna Kea testbed, and MSH spiders to Chaitén 2 March 2010
Posted by admin in Chaitén, Chile, current research, Hawaii, Indonesia, Krakatau, United States.Tags: Anak Krakatau, astrobiology, Chaitén, Chile, Hawaii, hydrothermal vents, Mauna Kea, Yellowstone
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Hydrothermal vents sometimes colonized from afar (Science News) – ‘Field studies at a hydrothermal vent system where all life was snuffed out by a massive undersea volcanic eruption reveal that these habitats can be repopulated in a matter of months by larvae from distant vents. … Water samples taken near the vents in May 2006 contained the larvae of Ctenopelta porifera, a rock-clinging gastropod called a limpet. By July, these fast-growing creatures had colonized the rocks around the eruption-sterilized vents; by October, they were mature and reproducing. … the nearest hydrothermal system known to host that species is located more than 300 kilometers away.’
Recent Yellowstone earthquake swarm was the second-largest ever (Denver Post) – ‘The Yellowstone earthquake swarm that began on Jan. 17 and ended on Feb. 11 was the second-largest earthquake swarm ever at Yellowstone National Park, according to scientists at the University of Utah. … Not only was the swarm the second-largest ever recorded at Yellowstone but it was longer in time and included more earthquakes than last year’s swarm beneath Yellowstone Lake, which occurred in December 2008 and January 2009, according to the scientists.’
Krakatoa’s child smokes with magic fire in belly (The Age) – ‘As the boat approached Anak Krakatau, the atmosphere was eerie. The smoke of the seasonal forest fires drifting from Sumatra made visibility poor and, before we even sighted the volcano, we heard it: a deep, otherworldly rumble. Then, out of the haze, materialised the cone of Anak Krakatau. Within minutes, thick grey ash billowed out of its caldera into the sky.’
Into the mouth of a volcano (Astrobiology Magazine) – ‘Dr. Inge Ten Kate, a University of Maryland Baltimore County research assistant, led an expedition into a cinder cone atop Mauna Kea, Hawaii, to test the prototype for an instrument that will be a miniature laboratory to discover the composition of rocks and atmospheres on moons, asteroids, and planets across the solar system. … Why a volcano? “The terrain and composition are similar to what we expect to find on the Moon, asteroids, and Mars,” says Ten Kate. “Also, there will be outgassing from the volcano, so we can test our ability to measure trace gases in atmospheres. Finally, the differences among various areas on the volcano’s cinder cone will be subtle, so it’s a good test of our sensitivity and our ability to distinguish different regions.”‘
Mount St. Helens ‘spiders’ will get tryout on Chilean volcano (The Oregonian) – Geological ‘spiders’ packed with instruments to monitor the heaves, sighs and belches of Mount St. Helens, are expected to migrate south this month. Two of the contraptions are headed to Chaiten, a volcano in Chile that began erupting in 2008 after about 9,000 years of dormancy. … The machines helped give the USGS sufficient information to declare in January 2008 that Mount St. Helens recent eruptive phase was over. That kind of certainty is needed at Chaiten, said John Ewert, a volcanologist in the Volcano Disaster Assistance Program. “It’s always hard enough to know when they’ll start erupting,” said Ewert, part of the team that visited the Chilean volcano in January. “It’s even harder to tell when they’ll stop.”‘
Mayon alert level lowered to 1 2 March 2010
Posted by admin in activity reports, Mayon, Philippines.Tags: Mayon, Philippines, volcanic activity reports
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The Philippine Institute of Volcanology and Seismology (Phivolcs) has lowered the alert level for Mayon from 2 (‘moderate unrest’) to the lowest level of 1 (‘no eruption imminent’). Seismic activity at Mayon is well within normal parameters, there is little or no evidence of magmatic movement within the volcano, deformation measurements indicate deflation, sulphur dioxide emissions and steam emissions are normal, and crater glow indicates no intensification of activity. The Phivolcs Mayon bulletin for 2 March 2010 gives the details, along with a warning that there is a continuing danger from sudden small explosions and rockfalls within the 6-km-radius permanent danger zone around the volcano.
For all our Mayon coverage: Mayon « The Volcanism Blog.
News
Mayon alert level lowered to 1 – Phivolcs – Philippines Daily Inquirer, 2 March 2010
Information
Global Volcanism Program: Mayon – summary information for Mayon (0703-03=)
Philippine Institute of Volcanology and Seismology – website for Phivolcs
Chile: big quake = more volcanic activity? 2 March 2010
Posted by admin in Chile.Tags: Chile, earthquakes, natural hazards, plate tectonics
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The M8.8 earthquake that hit Chile at the weekend has raised the question of whether such large quakes have any effect on activity in nearby volcanoes. In Chile itself, geologists from Chile’s Observatorio Volcanológico Andes del Sur (OVDAS) have publicly ruled out any such connection; New Scientist, by contrast, has a headline excitedly claiming ‘Volcanic explosions expected in Chile quake’s wake’.
The New Scientist article refers to a research paper by Sebastian Watt, David Pyle and Tamsin Mather of the University of Oxford which appeared in Earth and Planetary Science Letters in 2008 (‘The influence of great earthquakes on volcanic eruption rate along the Chilean subduction zone’, Earth and Planetary Science Letters, vol. 277, nos. 3-4, 30 January 2009, Pages 399-407 [
doi:10.1016/j.epsl.2008.11.005]). This paper looked into a potential connection between earthquakes and increased local volcanic activity in Chile over the past two centuries, and concluded that there was some evidence of such a connection:
We show a significant increase in eruption rate following earthquakes of MW > 8, notably in 1906 and 1960, with similar occurrences further back in the record. Eruption rates are enhanced above background levels for ~ 12 months following the 1906 and 1960 earthquakes, with the onset of 3–4 eruptions estimated to have been seismically influenced in each instance.
Given the claim that the ‘enhanced’ eruption rates may manifest over around 12 months after the earthquake, OVDAS’s denial that the 27 February quake will produce an increase in volcanic activity is premature. However, the 2008 paper raises many questions about the nature of the mechanisms at work, the time lag involved, and the real significance of the phenomenon (an estimated 3-4 additional eruptions is not very many). As Erik Klemetti has just observed,
Complex systems have many inputs – maybe the volcano that erupts next week would have erupted with a magnitude 4 earthquake, maybe it would have erupted without an earthquake at all. To connect the two merely because they are temporally juxtaposed is not scientifically sound. There is evidence that there could be an effect on nearby volcanism after large earthquakes in some settings, however, it is far from proven.
A further point is that, whatever New Scientist‘s headline writer may think, not all volcanic activity is explosive, or even dangerous in any way. Increased volcanic activity does not necessarily equate to increased hazard – as David Pyle points out in the New Scientist article: ‘At volcanoes that are already active we might see an increase in steam explosions, but we don’t expect it to present a significantly increased danger’. So even if there is a volcano-earthquake connection, and the question very much remains open, it is not necessarily something people living in active subduction zones should consider an additional significant threat.
N.B. ‘Llaima, one of the largest and most active volcanoes in Chile, is back on the watch list’, says the caption to a dramatic picture of Llaima accompanying the New Scientist story. In fact Llaima has been ‘on the watch list’ (if that means ‘at higher alert’) since mid-February, but of course it increases the drama to imply that the raised alert level is the result of the earthquake, and if that misleads your readers, so what?
News
Descartan que volcanes Llaima y Villarrica estén con actividad irregular luego de terremoto – La Tercera, 28 February 2010
Descartan que el terremoto un aumento de la actividad volcánica – Europa Press, 1 March 2010
Completa normalidad se observa en volcanes de la zona – El Austral, 1 March 2010
Volcanic explosions expected in Chile quake’s wake – New Scientist, 1 March 2010
NASA Earth Observatory: Chaitén volcano and surrounding area 1 March 2010
Posted by admin in Chaitén, Chile, NASA Earth Observatory.Tags: Chaitén, Chile, NASA Earth Observatory
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At the NASA Earth Observatory a new natural colour image of Chile’s Chaitén volcano and the surrounding area has been published in the Natural Hazards category. Captured on 25 February 2010 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite, the image shows the large area of recent grey ash deposits around Chaitén volcano and the ash-choked rivers draining the area. The site of Chaitén town, dangerous and officially abandoned but still, apparently, a tourist magnet, can be seen at the mouth of the river to the south of the volcano.
Chaitén volcano and the surrounding area – NASA Earth Observatory, 26 February 2010
For all our Chaitén coverage: Chaitén « The Volcanism Blog.
