Italy ponders volcanic threat from Ischia 28 April 2010Posted by admin in Ischia, Italy, natural hazards, volcano monitoring, volcanoes.
Tags: Ischia, Italy, volcano monitoring
At the northern end of the Gulf of Naples in southern Italy lies the island of Ischia, a complex volcanic edifice with a long history of violent activity that last erupted in 1302 AD. It has a population of around 60,000 and is a popular tourist destination. Now the head of Italy’s civil protection service, Guido Bertolaso, is sounding alarm bells about the potential volcanic threat from Ischia in the Italian media (only a few weeks after his Istituto Nazionale di Geofisica e Vulcanologia counterpart Dr Enzo Boschi did the same thing over Mount Marsili).
During a press conference in which he discussed the range of volcanic risks faced by Italy, Bertolaso described Vesuvius ‘the biggest civil protection problem in our country’, but pointed the finger at Ischia as potentially the more immediate threat: ‘If I were to say what is potentially the volcano with a bullet in the chamber, I would say that it is not Vesuvius but the island of Ischia’. He said that since the eruption of 1302 the height of Mount Epomeo, the highest point of the island (which is a volcanic horst) has increased by 800 metres [EDIT, this should almost certainly be 300 metres, see comments below. FURTHER EDIT, the uplift is to ~780 metres a.s.l., but that's over the past 33,000 years - see note at the end of this post.] and that the magma chamber is ‘reloading’. However, whereas everybody knows that Vesuvius is an active volcano there is not the same perception of Ischia: this is clearly something that Bertolaso wants to change.
Bertolaso also discussed the need for better monitoring of active undersea volcanoes, and floated the idea of a Europe-wide volcanic ash monitoring network, in the wake of the disruption caused by Eyjafjallajökull.
(INGV’s monitoring page for Ischia is here. There is no sign of any impending eruption at Ischia, as Bertolaso made clear in his remarks.)
NOTE: Ischia uplift. Poli et al (1989) note that ‘the rapid uplift of the central horst of Mount Epomeo … from about -200 m to 700 m occurred after 33,000 y. B.P., mostly in the last 20,000 years’ (p. 332). Poli et al also anticipated that the main potential volcanic hazard at Ischia was landslides and mudflows consequent on this rapid uplift, rather than the direct effects of volcanic activity, with future eruptions likely to be effusive rather than explosive, although there remains the possibility of ‘phreatic or phreatomagmatic crisis’ (p. 334). S. Poli et al, ‘Time dimension in the geochemical approach and hazard estimates of a volcanic area: the Isle of Ischia case (Italy)’, Journal of Volcanology & Geothermal Research, 36 (1989), pp. 327-335 [doi:10.1016/0377-0273(89)90077-2].
Bertolaso: allarme eruzione a Ischia – Corriere della Sera, 27 April 2010
Bertolaso lancia l’allarme su Ischia ‘Un vulcano con il colpo in canna’ – La Repubblica, 27 April 2010
Vulcani: Bertolaso, parte il monitoraggio di quelli sommersi – AGI, 27 April 2010
Bertolaso propone sistema monitoraggio Ue per ceneri vulcaniche – Reuters, 27 April 2010
Ischia volcano eruption concerns – Press Association, 28 April 2010
Italy says Ischia volcano, near Naples, could blow – The Statesman, 28 April 2010
Marsili seamount: tsunami threat for Southern Italy? 30 March 2010Posted by admin in Italy, Marsili, natural hazards, submarine volcanism, volcano monitoring, volcanoes.
Tags: Italy, Marsili, natural hazards, seamounts, tsunamis, volcano monitoring
Mount Marsili is a 3000-metre high seamount beneath the Tyrrhenian Sea, 150 km south-west of Naples. Marsili is active and recent research has indicated signs of restlessness (see this 2006 paper in PDF), although the risks of any dangerous eruptive activity are very slight). In an interview with the Italian newspaper Corriere della Sera, the director of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Dr Enzo Boschi, has reminded everyone that Marsili is active and that there is a potential threat of an eruption/collapse generating a tsunami that would threaten Southern Italy:
It could happen tomorrow. The latest research says that the volcanic edifice is not strong and its walls are fragile. Furthermore we have measured the magma chamber that has formed in recent years and it is of large dimensions. All this tells us that the volcano is active and could erupt unexpectedly.
According to the article, observations indicate that hydrothermal emissions from vents around Marsili have become more intense recently, and evidence of landslides discovered by the oceanographic research vessel Urania last February ‘indicate an instability impossible to ignore’. Dr Boschi warns that a flank collapse at Marsili ’would displace millions of cubic metres of material, which would be capable of generating a wave of great power’. Marsili is currently unmonitored, observes Dr Boschi: ‘A network of seismometers should be installed around the edifice, connected on land to a volcano monitoring centre. But this is beyond the budget’.
And it seems reasonable to suggest that the budget is what this article is actually all about. Despite the new attention this story will bring to Marsili as it gets cut-and-pasted around the web, there is nothing substantially new here, as Aldo Piombino notes in a very comprehensive post published on his blog today. No new activity lies behind this report, and nor has the potential threat, such as it is, changed in any way. The novelty, he observes, is in public attention being drawn to the need to monitor Marsili, which has been invisible in every sense as far as the Italian public is concerned.
Undersea volcanoes tend to be out of sight and out of mind. Writing in 2008, Aldo Piombino called Marsili ’one of the least-known of the huge volcanic systems of Europe’, and argued that more attention must be paid to this active and potentially very destructive underwater giant:
It is statistically very unlikely that in our lifetimes we will see an explosion of Marsili, and even less likely that we will see a tsunami caused by a landslide on its flanks, but it is to be hoped that it will be placed under close seismic and geochemical surveillance, as with other active Italian volcanoes. I believe that it is necessary for civil protection and for science that one of the largest volcanoes in Europe is better understood.
Boris Behncke of the INGV discussed Marsili’s activity in the course of his Q&A on Dr Klemetti’s Eruptions blog last year, but also remarked that monitoring Marsili was not a priority for the INGV [UPDATE: in fact that is not what Boris meant. He meant that Marsili has not been a priority for the Italian authorities, Civil Defence, and the Italian public, rather than the INGV - see his comment at Eruptions]. Dr Boschi’s comments today would seem to indicate that that has changed. Aldo Piombino observes today that the technology is available within the INGV to monitor Marsili directly from the seabed using new broadband seismometers transmitting to land-based monitoring stations, and supports Dr Boschi’s call for full monitoring of the volcano. But that cannot happen without money, which is more likely to be forthcoming if the potential (and real but, it must be emphasized again, very remote) dangers of a tsunami-generating collapse at Marsili are stressed – hence the Corriere della Sera article.
So, it seems that a push has begun within Italian volcanology to get Marsili wired up for continuous and comprehensive monitoring. Let us hope it succeeds.
Torna a far paura il vulcano sommerso nel Tirreno – Corriere della Sera, 29 March 2010
Undersea volcano threatens southern Italy: report – AFP, 29 March 2010
Il Monte Marsili, un gigantesco vulcano nascosto dalle profondità del Mar Tirreno – scienzeedintorni, 4 April 2008
Finalmente alla ribalta il più grande fra i vulcani sommersi nel Tirreno, il Monte Marsili – scienzeedintorni, 29 March 2010
Dr Boris Behncke Q&A at Eruptions 25 November 2009Posted by admin in volcanoes.
Tags: Boris Behncke, Italy, volcanology
If you want to know about the volcanoes of Italy, Dr Boris Behncke of the Istituto Nazionale di Geofisica e Vulcanologia is your man. Dr Behncke features in Erik Klemetti’s second volcanologist Q&A over at the Eruptions blog, and as you might expect the result is a volcanological feast. Highly recommended – part 1 is here, and part 2 is soon to follow.
UPDATE 27 Nov 2009. More very good questions and excellent answers: Part 2 of Boris Behncke’s Eruptions Q&A is now available here.
Another volcanologist Q&A at Eruptions: Boris Behncke 30 October 2009Posted by admin in Etna, Italy.
Tags: Etna, geoblogs, Italy, volcano research
Following on from the fascinating Chaitén question and answer session he set up at Eruptions with Dr Jonathan Castro, Erik Klemetti has organized a second volcanologist Q&A session, this time with Boris Behncke of the Italian National Institute of Geophysics and Volcanology in Catania.
Boris is a long-established and very good friend of this blog and of Eruptions, and volcano-followers here and elsewhere know him well as someone who is always ready to answer questions and share his expertise both on Etna and Italian volcanoes and on volcanological issues, both scientific and cultural, more widely. So, get your questions together for Boris Behncke and head over to Eruptions!
Saturday Volcano Art: Tivadar Kosztka Csontváry, ‘Ruins of the Greek Theatre at Taormina’ (1904-5) 24 October 2009Posted by admin in Saturday volcano art.
Tags: Etna, Hungarian art, Italy, Saturday volcano art, Tivadar Kosztka Csontváry
The view of Mount Etna from the Greek Theatre at Taormina is one which has featured in Saturday Volcano Art before: back in March I wrote about ‘Mount Etna from Taormina, Sicily’, painted by the American artist Thomas Cole in 1843. The painting above was completed some sixty years later by a very different artist, and conveys a very different mood.
‘Ruins of the Greek Theatre at Taormina’ was painted by the Hungarian artist Tivadar Kosztka Csontváry (1853-1919). Csontváry was a painter of visionary, mystical temperament who claimed that his vocation as an artist was revealed to him by God. Before this he had worked as a pharmacist. The revelation of his artistic destiny came to him in 1880; he spent the next fourteen years preparing himself by travelling, visiting artists and galleries, and earning enough money to pay for formal training in painting, which he began in 1894. He studied with artists in Germany and in Paris, and began producing his own paintings from 1895.
Csontváry painted intensely visionary religious scenes, mystically-charged landscapes both urban and rural, and some remarkable pictures based on his Italian travels, including views of Pompeii and the Bay of Naples. ‘Ruins of the Greek Theatre at Taormina’, which he painted in 1904-5, combines themes that recur repeatedly in his work: the way the past haunts the landscapes of the present, the tension between transience and timelessness, the scale and grandeur of nature. Csontváry’s highly developed theory of colour can be seen in the carefully balanced relationships between blue and yellow in the sea and the lower sky, and the dark reds and greens of the ruins and the landscape. The gradations of colour in the bay beneath the volcano and the bold diagonal of the cloud that reaches out from its slopes give the picture a quality of restlessness, while the snow-capped summit of Etna, white and ethereal, seems to possess an almost spiritual intensity. Yet there is an air of inhuman desolation about Csontváry’s vision that contrasts with Thomas Cole’s lush and harmonious classicism. For Csontváry the volcano is the presiding spirit of a beautiful landscape, but a spirit that remains bleak, remote, and indifferent.
[My attention was drawn to Csontváry's work by some comments left by Hungarian readers of this blog. My thanks to them for providing the topic for this week's Saturday Volcano Art, and for making me aware of the work of this remarkable and extraordinary Hungarian painter.]
For all ‘Saturday volcano art’ articles: Saturday volcano art « The Volcanism Blog.
Saturday Volcano Art: Bacchus and Vesuvius 17 May 2009Posted by admin in Italy, Saturday volcano art, Vesuvius.
Tags: Italy, Saturday volcano art, Vesuvius
Did Pliny the Elder, perhaps the most notable casualty of the 79 AD eruption of Vesuvius, know that the mountain looming over the Bay of Naples was a volcano? There is no hint of it in his Natural History, where in Book III he simply mentions in passing that Pompeii, Herculaneum and Neapolis are near Mount Vesuvius (III, 62). Later in the same book (III, 92-3) he writes of the volcanic nature of the Aeolian Islands, where sulphur was mined, but says nothing about volcanic activity in Campania.
The volcanic nature of Vesuvius was recognized by the Greek geographer Strabo who wrote in Book V, Chapter IV of his Geography (published around 7 BC) that the summit of Vesuvius ‘shows pore-like cavities in masses of rock that are soot-coloured on the surface, these masses of rock looking as though they had been eaten out by fire; and hence one might infer that in earlier times this district was on fire and had craters of fire, and then, because the fuel gave out, was quenched’. The Romans seem to have been unaware of Strabo’s work, but references to Vesuvius’s once ‘fiery’ nature also appear in Vitruvius’s De Architectura (Book II, Chapter VI), written around 25 BC, and in the Bibliotheca Historica of Diodorus Siculus (Book IV, Chapter I). Contemporaries did not connect the earthquakes that shook the area around the Bay of Naples in 62 and 63 with any volcanic activity. Vesuvius, for the people living around it in the first century AD, was a green, forested and vine-clad mountain, its crater silent and overgrown.
This is the Vesuvius shown in the wall-painting above, which comes from the ‘House of the Centenary’ in the southern part of Pompeii. The volcano is shown as tall, steep-sided, and green with vegetation. The figure of Bacchus, god of wine, stands before the mountain clad in grapes and holding a vine-leaf-capped staff. Wine drips from a glass in his hand, to be eagerly lapped up by an attendant panther (Bacchus is often represented with panthers having been, according to some legends, nursed by the animals when young). In the lower portion of the image is a serpent representing the agathodaemon, the spirit of fertility that inhabited the local fields and vineyards.
Roman landscape wall-paintings expressed ideas of beauty and fertility infused with sacred meaning. This image of Vesuvius thus works on several levels simultaneously, representing the natural landscape as harmoniously beautiful, richly fertile, and charged with supernatural as well as natural potency. Mount Vesuvius, guarded by the vine-god Bacchus and the agathodaemon vegetation-spirit, is here the central image in a visual and spiritual celebration of the local landscape and its fertility. The volcano is peaceful and unthreatening, its tranquil vine-clad slopes giving no hint of the destructive powers that lurk within.
The eruption of 79 AD unleashed pyroclastic flows that engulfed the House of the Centenary along with the rest of the Roman towns of Pompeii and Herculaneum — and incidentally preserved this serene wall-painting of the destroyer for posterity.
[This week's Saturday Volcano Art has come out on Sunday. Apologies for the delay.]
For all ‘Saturday volcano art’ articles: Saturday volcano art « The Volcanism Blog.
A look at Vesuvius: closely-watched volcano 22 April 2009Posted by admin in Italy, natural hazards, Vesuvius, volcano monitoring.
Tags: Italy, natural hazards, Vesuvius, volcano monitoring
Under the headline ‘the world’s most closely watched volcano’, AFP have published an interesting article, with pictures, about the monitoring of Vesuvius.
The article describes how sensors continuously watch various aspects of the volcano’s activity, and that information is passed to the Vesuvius Observatory in Naples (the world’s oldest volcanological observatory), where it is constantly monitored and assessed. If a major eruption appears to be in prospect, the current emergency plan calls for 600,000 people from the 18 towns and cities within the 15-kilometre-radius ‘red zone’ around Vesuvius to be evacuated.
This would take about two weeks.
Vesuvius, the world’s most closely watched volcano – AFP, 22 April 2009
Tags: Etna, Italy, volcano art, volcano culture, volcano images
‘What a magnificent site! Etna with its eternal snows towering in the heavens — the ranges of nearer mountains — the deep romantic valley … I have never seen anything like it’. So wrote the American artist Thomas Cole (1801-48) of Taormina in Sicily, which he visited in April 1842. While staying at Taormina he climbed Mount Etna, and made many sketches of the landscape and the Greek and Roman remains that were to be found there. When he returned to the United States he produced several large paintings based on his time in Sicily, of which ‘Mount Etna from Taormina’ is one of the most notable.
Cole is perhaps chiefly known and celebrated today as an artist of the American landscape, and particularly of the Hudson River Valley and the Catskill Mountains. He sought in his art to represent the American landscape as an unspoilt Eden, steeped in natural rather than cultural antiquity, yet the spirit of the Italian landscape, shaped by the hand of man and haunted by history, is always present in his work. He was an artist with a deep sense of the past and a moralizing vision: he was profoundly attracted by the tranquility and harmony of the Italian landscapes he saw and painted during his two visits to Italy in 1830-32 and 1841-2, and which he continued to recreate throughout his career, but just as his American landscape views are haunted by the cycle of natural destruction and renewal, so his Italian views are deeply imbued with the presence of antiquity and the lessons of human pride and folly.
Cole’s view of Etna is structured into three zones, following established classical landscape tradition: foreground, middle ground and distance. The foreground represents the past, in the form of the ancient Teatro Greco, the Greek theatre (although most of the presently visible structure is Roman), one of the celebrated sights of Taormina. Beyond the ruined arches and broken columns of the theatre lies the present, in the form of the cultivated valley in which man and nature exist in pastoral harmony. Still further beyond, and dominating the canvas, is Mount Etna, representing the eternal. Cole thus imbues his landscape with a narrative meaning, reflecting on the long history of human civilization and yet its relative insigificance and fragility compared with the eternal forces of divinely-ordered nature.
Brigitte Bailey, ‘The panoptic sublime and the formation of the American citizen in Cooper’s Wing-and-Wing and Vole’s Mount Etna from Taormina, Sicily‘ (1997) [online here]
Louis L. Noble, The Life and Works of Thomas Cole, N.A. (New York, 1853)
Barbara Novak, American Painting of the Nineteenth Century: Realism, Idealism, and the American Experience (1980; 3rd edn., New York: Oxford University Press, 2007)
Thomas Cole Online (Artcyclopedia)
Wilderness Art of the 1800s (Idaho State University)
Tags: Italy, Vesuvius, volcano art, volcano culture, volcano images
Xavier Della Gatta, ‘Eruption of Vesuvius’ (1794). Watercolour.
Xavier Della Gatta (1758-1828) was one of many Neapolitan artists of the latter part of the eighteenth century who specialized in painting local scenes for visitors who came to Naples on the ‘Grand Tour’ to see the city, the antiquities, the landscape, and, not least, the volcano. Mount Vesuvius was highly active during this period and Della Gatta produced many paintings of spectacular volcanic activity for his wealthy and cultured clientele.
The picture above depicts the eruption of June 1794 and is perhaps most notable for its detailed depiction of the volcano’s plinian eruption column – indeed, it could be said that the eruption column rather than the volcano producing it is the true subject of the picture, dominating the canvas and dividing the scene sharply into light and dark. Della Gatta has distinguished the darker, denser clouds of ash in the lower part of the column from the lighter, more vaporous plume that blows away to the north-east in the upper left of the canvas. The column twists as the winds play upon it, lightning flickers within it, and ashfall can be seen on the landward side of the volcano.
Della Gatta’s blend of careful observation and crisp, precise depiction of detail recommended him to Sir William Hamilton, who commissioned him to illustrate some of the reports on Vesuvius’s activity which he compiled for the Royal Society following the death of his earlier collaborator (and Della Gatta’s teacher) Pietro Fabris in 1792. Hamilton’s description of the June 1794 eruption column was published in the Royal Society’s Philosophical Transactions the following year:
… the black smoke and ashes issuing continually from so many new mouths, or craters, formed an enormous and dense body of clouds over the whole mountain, and which began to give signs of being replete with the electrical fluid, by exhibiting flashes of that sort of zig-zag lightning, which in the volcanic language of this country is called ferilli, and which is the constant attendant on the most violent eruptions. From what I have read and seen, it appears to me, that the truest judgment that can be formed of the degree of force of the fermentation within the bowels of a volcano during its eruption, would be from observing the size, and the greater or less elevation of those piles of smoky clouds, which rise out of the craters, and form a gigantic mass over it, usually in the form of a pine tree, and from the greater or less quantity of the ferilli, or volcanic electricity, with which those clouds appear to be charged.*
The June 1794 eruption was very destructive. Lava flows from lateral fractures on the south-west flank of the volcano reached the sea, completely destroying the town of Torre del Greco on the way, and Naples was seriously affected by earthquakes and heavy ashfall. Della Gatta painted several pictures of the eruption, but none conveys the power, drama and grandeur of the event quite as effectively as the one reproduced here.
* Sir William Hamilton, ‘An account of the late eruption of Mount Vesuvius’, Philosophical Transactions of the Royal Society of London, vol. 85 (1795), pp. 73-116, here pp. 80-81.
The ups and downs of Vesuvius 17 September 2008Posted by admin in current research, geoscience, Italy, natural hazards, Vesuvius.
Tags: Italy, natural hazards, Vesuvius, volcanology
A new study of Vesuvius suggests that the magma source involved in the eruptions of the last 20,000 years or so has been rising within the volcano, so that the more recent the eruption, the shallower the depth from which its magmas have come. Does this mean, looking to the future, that Vesuvius is more or less dangerous than we thought? Well, that depends…
The research in question was done by a Franco-Italian team of scientists and the results have been published as a letter in the 11 September 2008 issue of Nature under the title ‘Upward migration of Vesuvius magma chamber over the past 20,000 years’ (link is to abstract only). Analysis of samples of material from four of Vesuvius’s main explosive events between 5800BC and 472AD indicates that the pressure to which magmas have been subjected before each event has progressively reduced with each successive eruption: the scientists’ conclusion is that the magma chamber has been moving upward within the volcano, from 7-8km to 3-4km depth between 79AD and 472AD. If data from the Pomici di Base event of 18.5kyr ago and the most recent major eruption of 1944 is taken into account, the total upward migration of the magma chamber is around 9-11km.
The significance of this is explained by Dr Erik Klemetti in his crystal-clear discussion of this research at Eruptions: magma at shallower depths is subject to lower pressure, which means less chance of the explosive degassing that produces violent eruptions. However, he goes on to point out that this research, focused as it is on this ascending and recently tapped magma source, has nothing to say about future eruptions that might be rooted deeper in the system, produced by the influx of fresh magma at depth.
The authors of the Nature study, as is the way of such things, conclude very circumspectly by saying that the apparent upward migration of the magma chamber needs to be incorporated into the predictive models used to forecast the future behaviour of the volcano, and that more research is needed. They don’t make any predictions about the future. Reporters writing up their research are not so coy, so we have stories apparently using the same facts to draw diametrically opposed conclusions: ‘Mount Vesuvius’ destructive power may be diminishing’, ‘Vesuvius magma chamber rising; may mean milder eruption’, and ‘Mount Vesuvius may be less dangerous than predicted’ on the one hand, and ‘Pompeii-style eruption of Vesuvius can’t be ruled out’, ‘Vesuvius still an eruption risk’, on the other. How apocalyptic are you feeling at the moment? Take your pick accordingly.
- B. Scaillet, M. Pichavant & R. Cioni, ‘Upward migration of Vesuvius magma chamber over the past 20,000 years’, Nature, no. 455 (11 September 2008). Link to abstract.
Image: Naples and Vesuvius, August 2003 (source).
Vesuvius magma chamber rising; may mean milder eruption – National Geographic, 10 September 2008
Mount Vesuvius may be less dangerous than predicted – Scientific American, 10 September 2008
Pompeii-style eruption of Vesuvius can’t be ruled out – AFP, 11 September 2008
Mount Vesuvius’ destructive power may be diminishing – Discover Magazine, 11 September 2008
Vesuvius still an eruption risk – ABC Science, 11 September 2008