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British scientists discover deepest known undersea volcanic vents 12 April 2010

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First photograph of the world's deepest known 'black smoker' vent, erupting water hot enough to melt lead, 3.1 miles deep on the ocean floor (National Oceanography Centre)
First photograph of the world’s deepest known ‘black smoker’ vent, erupting water hot enough to melt lead, 3.1 miles deep on the ocean floor (National Oceanography Centre).

Scientists from the UK’s National Oceanography Centre (NOC) have discovered the deepest volcanic vents so far known, 5000 metres below the surface of the Caribbean Sea. The vents are located in the Cayman Trough in the western Caribbean, which reaches a maximum depth of 7,500 metres. Further research will analyse the geology and geochemistry of the vents and the marine life associated with them. NOC geochemist Dough Connelly, Principal Scientist of the expedition, says: ‘We hope our discovery will yield new insights into biogeochemically important elements in one of the most extreme naturally occurring environments on our planet’.

The Cayman Trough expedition, funded by the National Environment Research Council, is based aboard the UK’s new ocean-going research vessel RRS James Cook. For more on the expedition, see our post from August 2008: British scientists to investigate Caribbean deep-sea hydrothermal vents.

News
British scientific expedition discovers world’s deepest known undersea volcanic vents – EurekAlert, 11 April 2010
World’s deepest undersea vents discovered in Caribbean – BBC News, 12 April 2010
World’s deepest known undersea volcanic vents discovered – ScienceDaily, 12 April 2010

Information
National Oceanography Centre – website for the UK’s newly integrated National Oceanography Centre
Cayman Trough expedition – reports from the expedition team

The Volcanism Blog

Marsili seamount: tsunami threat for Southern Italy? 30 March 2010

Posted by admin in Italy, Marsili, natural hazards, submarine volcanism, volcano monitoring, volcanoes.
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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.

UPDATE 30 March 2010: Dr Erik Klemetti has more on Marsili at Eruptions, and Boris Behncke, himself of the INGV (Dr Boschi is Boris’s boss), has an illuminating comment here.

News
Torna a far paura il vulcano sommerso nel TirrenoCorriere 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

The Volcanism Blog

Seamounts galore in Oceanography special issue 24 February 2010

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Oceanography special issue: Mountains in the Sea (23:1 Mar 2010)

The latest issue (vol. 23, no. 1, March 2010) of the official magazine of The Oceanography Society, Oceanography, is devoted to the study of undersea mountains or seamounts. This special issue is entitled, not surprisingly, ‘Mountains in the Sea’ and features fascinating content by some very distinguished contributors, and, best news of all, the online version is free!

Seamount volcanism is an important theme in many of the articles, as might be expected. The following focus particularly on volcanic matters (links are direct to the PDFs):

There are also spotlight articles on particular seamounts, including the volcanically active Loihi, Vailulu’u and Northwest Rota-1 seamounts (links are direct to the PDFs).

The table of contents for this special issue of Oceanography gives direct links to all the content, and USGS director Marcia McNutt provides a foreword (PDF). Also: Oceanography home page, The Oceanography Society home page, and a press release at ScienceDaily.

The Volcanism Blog

Undersea volcanic action on video 10 June 2009

Posted by admin in eruptions, Pacific, submarine volcanism.
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Over at Discovery News there’s a fascinating report on the undersea eruptive activity revealed at West Mata in the South Pacific by a team of scientists investigating neovolcanism in the NE Lau Basin. There is some dramatic video footage of the actively erupting (and appropriately-named) Hades and Prometheus vents on West Mata, captured by the team’s Jason-2 ROV.

Undersea volcanic eruptions spotted in action – Discovery News, 5 June 2009

The Volcanism Blog

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

Scientists return to active undersea volcano 20 March 2009

Posted by admin in current research, geoscience, Pacific, submarine volcanism.
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In 2004 an international team of scientists using a remotely-operated submersible witnessed an undersea volcanic eruption for the first time at Northwest Rota-1, a seamount rising to 517 metres below the sea surface in the Mariana Islands. Further scientific studies were carried out at the site in 2005 and 2006. Last year hydrophones recorded sounds of eruptive activity at the site.

In April this year the scientific team will be returning to Northwest Rota-1 for further studies, says a press release from Oregon State University:

During the two-week project, the scientists will deploy long-term monitoring instruments including hydrophones, chemical sensors, current meters and plume sensing devices that will allow them to study for the first time the patterns of activity over an entire year. They also will make additional visual observations of the eruptive activity, hydrothermal vents and biological communities, and will collect samples of lava, gas and fluids from the volcano.

It will be fascinating to see what they come up with. The NOAA website for the April 2009 cruise can be found here: Vents Program: Marianas.

The Volcanism Blog

Hunga Tonga-Hunga Ha’apai update, 20 March 2009 20 March 2009

Posted by admin in activity reports, eruptions, Pacific, submarine volcanism, Tonga.
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Tonga submarine eruption, 20 March 2009 0130GMT (NASA Aqua image)
Above: MODIS image from NASA Aqua satellite captured at 01:30 GMT on 20 March 2009. The island of Tongatapu is at the lower edge of the image. The site of the eruption is marked by the yellow arrow: a small plume can be seen extending ENE, and floating ash is staining the sea around the volcano greenish-blue. [source]

Eruptive activity at Hunga Tonga-Hunga Ha’apai appears to have declined somewhat over the last 12 hours, according to the latest advisory from Wellington VAAC (10:29 GMT 19 March 2009). The VAAC advisory, based on pilot observations and satellite imagery, reports ‘no more active eruptions, steaming to 6000ft [1800 metres]‘, with ‘white and wispy ash haze extending to large areas ENE blw 5000ft [below 1500 metres]‘. An earlier advisory (17:58 GMT 19 March 2009) reported frequent eruptions and ash clouds to FL130 (13000 feet, 4000 metres), with a plume extending 300 miles (480 kilometres) ENE.

At 01:30 GMT today NASA’s Aqua satellite captured a MODIS image which showed only a small plume extending less than 10 kilometres ENE of the volcano (from the NASA MODIS Rapid Response site: original image is here, detail reproduced above).

The BBC has some fresh video of the eruption from the inspection trip made by Tongan geologists yesterday. CBS News has the AP report of the eruption, with added video, pictures, and the usual mad/dumb/hilarious comments from the visiting public; they also have a short photo essay on the eruption (titled, in typically odd CBS fashion, ‘Undersea Volcano Erupts Photos’). And the Boston Globe’s ‘Big Picture’ feature lives up to its name with spectacular big, big pictures of the eruption.

As if this eruption wasn’t enough of a reminder that Tonga is situated in a geologically highly active part of the planet, there was a magnitude 7.9 earthquake in the Tongan Arc yesterday. There is no reason to suspect a direct link to the eruption. A tsunami alert was issued following the earthquake, but was later cancelled because it was ‘a tiny tsunami … nothing to worry about’.

UPDATE: Lousy science reporting from the BBC, who are asserting on the basis of no evidence at all that ‘An earthquake may have triggered an underwater volcano to erupt’. Nice video, clueless commentary: Quake may have caused eruption. Additional update, Dr Klemetti at Eruptions is also irritated by this stuff: ‘absolutely terrible “science” journalism … silly note of dread … all conjecture’.

For all our coverage of the Tonga eruption: Tonga « The Volcanism Blog.

News
Undersea volcano making waves in the Pacific – CBS News, 19 March 2009
Volcano shatters Pacific calm around TongaThe Independent, 20 March 2009
South Pacific volcano inspected – BBC News, 20 March 2009

Information
Global Volcanism Program: Hunga Tonga-Hunga Ha’apai – summary information about Hunga Tonga-Hunga Ha’apai (0403-04=)
Tonga volcanoes and volcanics – overview from the USGS

The Volcanism Blog

More on Hunga Tonga-Hunga Ha’apai 19 March 2009

Posted by admin in eruptions, Pacific, submarine volcanism, Tonga.
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The eruption is ongoing at Hunga Tonga-Hunga Ha’apai: the latest volcanic ash advisory from Wellington VAAC, issued at 05:23GMT today, reports ash emissions at FL130 (13000 feet or about 4000 metres), expected to rise to FL150 (15000 feet or about 4500 metres) over the next few hours. The Aviation Herald quotes Airways New Zealand reports of ash up to 15km, but VAAC statements give no confirmation of this figure.

The Aqua MODIS image of the Hunga Tonga-Hunga Ha’apai eruption that we were able to preview on this blog yesterday (thanks to our friends at NASA) is now available at the NASA Earth Observatory, in the ‘natural hazards’ category: Submarine Eruption in the Tonga Islands (18 March 2009). The image comes with the usual annotations and detailed commentary.

BBC News has a video of the eruption (some stills from the same video can be found at our earlier post) which is a beautiful case study in hydrovolcanic phenomena: voluminous steam clouds, violent explosive activity, dark and rapidly expanding eruptions of volcanic ejecta, debris clouds spreading across the ocean. Spectacular stuff. The video also shows clearly that there are currently two active vents.

Associated Press reports Tongan authorities saying that ‘there have been no reports of fish or other animals being affected’. This seems on the face of it unlikely, and is contradicted by other reports. A TVNZ report on the eruption says that ‘Boaties who were close by when the eruption took place talked of burning birds falling from the sky’ and that ‘wildlife from the island closest to the eruption have been completely destroyed’, while ABC Radio Australia quotes a Tongan journalist: ‘There were lots of dead fishes and dead birds’.

Tongan government geologists will be making an inspection of the area by boat today. They couldn’t go earlier, as no-one could agree who should pay the Tongan Navy for the fuel the trip would use.

For all our coverage of the Tonga eruption: Tonga « The Volcanism Blog.

Information
Global Volcanism Program: Hunga Tonga-Hunga Ha’apai – summary information about Hunga Tonga-Hunga Ha’apai (0403-04=)
Tonga volcanoes and volcanics – overview from the USGS

News
Underwater volcano erupts off Tonga – BBC News, 19 March 2009
Underwater volcano sends huge columns of ash into Pacific skyThe Times, 19 March 2009
Underwater volcano continues erupting – TVNZ, 19 March 2009
Tongan inspection team heads to undersea volcano – Associated Press, 19 March 2009
Tonga officials inspect volcano’s environmental impact – ABC News, 19 March 2009
Tonga undersea volcano hampers Pacific air trafficAviation Herald, 19 March 2009
Undersea volcano erupts off Tonga – Press Association, 19 March 2009
Geologists inspect underwater volcano site off Tonga – ABC Radio Australia, 19 March 2009
Visual checks to be made of underwater volcano – Radio New Zealand, 19 March 2009

The Volcanism Blog

Hunga Tonga-Hunga Ha’apai eruption images 19 March 2009

Posted by admin in eruptions, Pacific, submarine volcanism, Tonga.
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A Japanese reader of The Volcanism Blog has sent in the following images of the Hunga Tonga-Hunga Ha’apai eruption, captured from a video taken on 18 March 2009.

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

Hunga Tonga-Hunga Ha'apai eruption, 18 March 2009

These images clearly show that there are two active vents. The white plume consists mainly of steam, the dark masses are dark pyroclastic material projected violently upwards as water enters the magmatic vents, creating powerful phreatic explosions. The ragged-edged effect visible on the dark clouds is caused by larger fragments of ejected material following parabolic curves as they are hurled upwards and outwards, trailing smaller fragments behind them.

UPDATE: The video from which these images are clearly taken has turned up on the BBC News website: Underwater volcano erupts off Tonga. At the end of the video, around the point from which the final image reproduced above comes, voices can be heard off-camera saying ‘I think we should run away’, and ‘turn the boat around’.

For all our coverage of the Tonga eruption: Tonga « The Volcanism Blog.

Information
Global Volcanism Program: Hunga Tonga-Hunga Ha’apai – summary information about Hunga Tonga-Hunga Ha’apai (0403-04=)
Tonga volcanoes and volcanics – overview from the USGS

The Volcanism Blog

Satellite image of Tonga eruption 18 March 2009

Posted by admin in activity reports, eruptions, Pacific, submarine volcanism, Tonga.
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The MODIS equipment on NASA’s Aqua satellite captured a true-colour image of the submarine eruption of Hunga Tonga-Hunga Ha’apai in Tonga at 01:45GMT (14:45 local time) on 18 March 2009. The full-size image can be found at the NASA MODIS Rapid Response site. Below is a detail of the image showing the eruption (yellow arrow). North is at the top; the island at the lower edge is Tongatapu Island, where the Tongan capital Nuku’alofa is located, while upper right are the islands of the Nomuka Group. The eruption is producing a dense plume of steam which shows up white against the ocean. Volcanic ash can be seen floating on the ocean surface around the plume.

Tonga submarine eruption, 18 March 2009 0145GMT (NASA Aqua image)

Click here to view the original full-size image (at 250m per pixel scale – other resolutions can be selected) at the NASA MODIS Rapid Response site. There is also now a nice clear mapped version here.

(Thanks to Robert Simmon of NASA for drawing my attention to this image.)

UPDATE: This image is now available at the NASA Earth Observatory, in the ‘natural hazards’ category: Submarine Eruption in the Tonga Islands (18 March 2009).

Information
Global Volcanism Program: Hunga Tonga-Hunga Ha’apai – summary information about Hunga Tonga-Hunga Ha’apai (0403-04=)
Tonga volcanoes and volcanics – overview from the USGS

The Volcanism Blog

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