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125 years after Tarawera erupted, New Zealand’s Pink and White Terraces found 10 June 2011

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On 10 June 1886 Mount Tarawera volcano in New Zealand erupted in a huge explosive event that devastated the surrounding countryside. The beautiful Pink and White Terraces at nearby Lake Rotomahana, which were among the most celebrated of New Zealand’s many natural wonders, were obliterated by the eruption.

However, it seems that substantial parts of the terraces survived after all, and are now lying at the bottom of Lake Rotomahana. New Zealand and United States scientists working to map the lake-bottom and the geothermal system beneath it using autonomous underwater vehicles discovered portions of the Pink Terraces at the beginning of this year, and now they have confirmed the discovery of parts of the White Terraces as well. The remains were identified with side-scanning sonar: ‘The two places on the lake floor where we encountered hard, up-standing crescent-shaped features correspond to the locations of the Pink and White Terraces before the Tarawera eruption’, says Dr Cornel de Ronde of GNS Science, leader of the project.

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On This Day: the Laki eruption begins, 1783 8 June 2011

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On This Day: 8 June 1783On 8 June 1783 a fissure eruption began across the flanks of the Laki volcanic mountain ridge in south-eastern Iceland. The Laki (or Lakagígar) eruption lasted until 8 February 1784: approximately 27 km of fissures ultimately opened, and 14.7 cubic kilometres of lava were erupted. This was a huge volume of material, but the lava did not itself directly cause any deaths. Much more deadly were the gas emissions (PDF) produced by the eruption. The Laki eruption released vast quantities of gas into the atmosphere: the majority was water vapour, but an estimated 10% is thought to have been composed of carbon dioxide, sulphur dioxide, hydrogen chloride and fluorine. A dry fog hung over Iceland, the North Atlantic and parts of adjacent land masses for weeks. The 50 million tonnes of sulphur dioxide combined with atmospheric water vapour to form sulphuric acid aerosols, and the resulting acid rain poisoned the soil and destroyed the grazing upon which Iceland’s livestock depended. Animals died in their tens of thousands, and the people followed: by the end of 1785 over 10,000 people had died, perhaps one-fifth of Iceland’s population, 9 out of 10 from famine. Nor were the effects limited to Iceland: the acidic haze erupted from Laki spread to Britain, Ireland and continental Europe, bringing fogs, acid rain, violently disturbed weather patterns and unseasonable temperatures, leading to damaged vegetation, failed harvests, hunger and poverty (in these circumstances, the French Revolution was inevitable). Beyond Europe, populations as far afield as North America, Egypt and Japan may have suffered the meteorological and economic consequences of the seven-month Laki eruption.

UPDATE. More on Laki 1783 from the fascinating History of Geology blog: 8 June 1783: the Laki eruptions.

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Mexico marks Jorullo’s 250th birthday 30 September 2009

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Mexico has been marking the 250th anniversary of the appearance of Jorullo volcano, a cinder cone in the Michoacán-Guanajuato volcanic field situated in the southern state of Michoacán. The eruption which produced Jorullo began on 29 September 1759 and continued for 15 years, with lava flows, ashfall and mudflows affecting the surrounding landscape. By the end of the eruption the cone had reached a height of 1320 metres, with a 400-metre-wide crater 150 metres deep, and Jorullo’s lava flows had covered 9 square kilometres around the volcano.

A number of events will be taking place in Mexico to mark the anniversary, including a conference organized by the Universidad Nacional Autónoma de México. Scientist Víctor Huco Garduño Monroy of the Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) has taken the opportunity of the anniversary to warn of the continuing dangers posed by volcanic activity in Michoacán:

Michoacán is located in an area of ‘high risk’ in terms of earthquakes and volcanic activity, as recorded in just over one thousand volcanic cones on the meseta purépecha, which has the potential to give rise to new volcanoes. However, there is as yet no state seismological network, nor any regional seismological or geological monitoring … There is a high rate of the emergence of new volcanoes that could in future give us a scenario like that of Paricutín or Jorullo.

The emergence of Paricutín in 1943 was the most recent eruptive activity in the
Michoacán volcanic field. Paricutín, like Jorullo, appeared from nowhere, gradually building into a cone 424 metres high and swallowing two villages and a large area of farmland before the eruption ceased in 1952. It is certain that the future will see similar eruptions in Michoacán – new Paricutíns, and new Jorullos.

News
Conmemorarán la aparición del Jorullo, el volcán más importante de MichoacánCambio de Michoacán, 28 September 2009
Inician festejos de aniversario del Nacimiento del Volcán El JorulloQuadratin, 28 September 2009
Michoacán, territorio de ‘alto peligro’ por la actividad volcánica y sísmicaLa Jornada Michoacán, 29 September 2009

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Krakatau, 27 August 1883 27 August 2009

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'View of Krakatoa during the earlier stage of the eruption. From a photograph taken on Sunday the 27th of May, 1883' - plate I from The Eruption of Krakatoa and Subsequent Phenomena (London, 1888)

It was 126 years ago today, on 27 August 1883, that the most recent large-scale eruption of Krakatau (or Krakatoa, if you prefer) reached its final cataclysmic stage. An appropriate day, then, to draw the attention of interested readers to the fact that possibly the most detailed contemporary scientific study of the eruption, the Royal Society’s 500-page report on The Eruption of Krakatoa and Subsequent Phenomena (1888), is freely available to download from the Internet Archive.

Fgures 2 and 3 from The Eruption of Krakatoa and Subsequent Phenomena (London, 1888)

The book has been fully digitized by Google, but it is a curious fact that Google chooses not to make the full text of this out-of-copyright publication available via Google Books. It is, however, freely available to read and download (along with many other texts that Google has digitized but has seemingly decided to keep to itself) through its inclusion in the Internet Archive.

The Eruption of Krakatoa and Subsequent Phenomena can be accessed via this page at the Internet Archive. The PDF of the entire book (27.2 MB) cannot be found via the ‘Google.com’ link given on that page, but can be downloaded through this direct link.

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Happy 10th birthday NASA Earth Observatory 30 April 2009

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Happy 10th birthday to the NASA Earth Observatory, which has been bringing us wonderful images of the Earth from space since 29 April 1999. Congratulations and many happy returns to the Earth Observatory and to all the hard-working people behind the scenes who have made it such a marvellous web resource for the last decade.

The voting for the ten favourite images of the day from the last ten years is now complete, and the winners are available for viewing here: Top 10 Images of the Day. Not a volcano among them, sadly, so to make up for that here’s a favourite of mine:

Chaitén volcano erupting, 19 January 2009 (NASA Aster/Terra image)
Chaitén volcano erupting, 19 January 2009. Captured by the ASTER equipment on NASA’s Terra satellite. Featured at the NASA Earth Observatory 22 January 2009.

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The Daily Volcano Quote: Darwin on volcanic islands 17 February 2009

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St. Louis, Mauritius.

It is singular in how many respects those portions of St. Jago and of Mauritius which I visited, agree in their geological history. At both islands, mountains of similar external form, stratification, and (at least in their upper beds) composition, follow in a curved chain the coast-line. These mountains in each case appear originally to have formed parts of one continuous mass. The basaltic strata of which they are composed, from their compact and crystalline structure, seem, when contrasted with the neighbouring basaltic streams of subaërial formation, to have flowed beneath the pressure of the sea, and to have been subsequently elevated. We may suppose that the wide breaches between the mountains, were in both cases worn by the waves, during their gradual elevation,—of which process, within recent times, there is abundant evidence on the coast-land of both islands. At both, vast streams of more recent basaltic lavas have flowed from the interior of the island, round and between the ancient basaltic hills; at both, moreover, recent cones of eruption are scattered around the circumference of the island; but at neither have eruptions taken place within the period of history. As remarked in the last chapter, it is probable that these ancient basaltic mountains, which resemble (at least in many respects) the basal and disturbed remnants of two gigantic volcanos, owe their present form, structure, and position, to the action of similar causes.

This excerpt from Geological Observations on the Volcanic Islands visited during the Voyage of H.M.S. Beagle (1844) is quite simply a wonderful example of Charles Darwin’s gifts of observation, theorization and imagination at work on the interpretation of landforms, not merely as they exist in space, but as they have come into being through time.

From Charles Darwin, Geological Observations on the Volcanic Islands visited during the Voyage of H.M.S. Beagle (London: Smith, Elder, 1844), p.31. Available online at The Complete Work of Charles Darwin Online.

For one week from 12 February 2009, the 200th anniversary of Charles Darwin’s birth, The Volcanism Blog will feature a volcano-related quote from Darwin each day.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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The Daily Volcano Quote: Darwin on Ascension 16 February 2009

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Lava flows on Ascension. Photographer Ben Tullis (Creative Commons license).

Those who have beheld a volcanic island, situated within an arid climate, will be able at once to picture to themselves the aspect of Ascension. They will imagine smooth conical hills of a bright red colour, with their summits generally truncated, rising distinct out of a level surface of black rugged lava. A principal mound in the centre of the island, seems the father of the lesser cones. It is called Green Hill; its name is taken from the faintest tinge of that colour, which at this time of the year was barely perceptible from the anchorage. To complete this desolate scene, the black rocks on the coast are lashed by a wild and turbulent sea. … One of my excursions took me towards the S.W. extremity of the island. The day was clear and hot, and I saw the island, not smiling with beauty, but staring with naked hideousness. The lava streams are covered with hummocks, and are rugged to a degree, which, geologically speaking, is not of easy explanation. The intervening spaces are concealed with layers of pumice, ashes, and volcanic tuft. In some parts rounded volcanic bombs, which must have assumed this form, when projected red-hot from the crater, lie strewed on the surface.

HMS Beagle called at Ascension Island in July 1836, on the homeward leg of the voyage she had begun, with the young Charles Darwin aboard, five years earlier. Darwin spent several days ashore, exploring the geology of the island: ‘I clambered over the mountains of Ascension with a bounding step and made the volcanic rocks resound under my geological hammer!’ These high spirits (as recalled in his Autobiography) were partly due to his having received at Ascension a number of letters from home, including one from his father which said that the Cambridge geologist Adam Sedgwick had predicted that he, Darwin, ‘should take a place among the leading scientific men’. Darwin’s explorations were the first geological studies of Ascension, which is a stratovolcano that rises more than 3000m from the Atlantic seafloor and has some varied and fascinating volcanic geology.

From Charles Darwin, Voyages of the Adventure and Beagle (London: Henry Colburn, 3 vols., 1839), vol. III, pp. 585-6, 588-9. Available online at The Complete Work of Charles Darwin Online.

Image: Lava flows on Ascension Island. Picture by Ben Tullis, reproduced here under a Creative Commons license. [source]

For one week from 12 February 2009, the 200th anniversary of Charles Darwin’s birth, The Volcanism Blog will feature a volcano-related quote from Darwin each day.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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The Daily Volcano Quote: Charles Darwin, geologist 13 February 2009

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Salisbury Crags and Arthur's Seat, Edinburgh (Przemyslaw Graczyk, Creative Commons License).

During my second year at Edinburgh I attended Jameson’s lectures on Geology and Zoology, but they were incredibly dull. The sole effect they produced on me was the determination never as long as I lived to read a book on Geology, or in any way to study the science. Yet I feel sure that I was prepared for a philosophical treatment of the subject; for an old Mr. Cotton in Shropshire, who knew a good deal about rocks, had pointed out to me two or three years previously a well-known large erratic boulder in the town of Shrewsbury, called the ‘bell-stone’; he told me that there was no rock of the same kind nearer than Cumberland or Scotland, and he solemnly assured me that the world would come to an end before any one would be able to explain how this stone came where it now lay. This produced a deep impression on me, and I meditated over this wonderful stone. So that I felt the keenest delight when I first read of the action of icebergs in transporting boulders, and I gloried in the progress of Geology. Equally striking is the fact that I … heard the Professor [Jameson], in a field lecture at Salisbury Crags, discoursing on a trapdyke, with amygdaloidal margins and the strata indurated on each side, with volcanic rocks all around us, say that it was a fissure filled with sediment from above, adding with a sneer that there were men who maintained that it had been injected from beneath in a molten condition. When I think of this lecture, I do not wonder that I determined never to attend to Geology.

In the above words, written in his Autobiography, Charles Darwin dismissed the extramural course in geology which he attended in 1826-7, the second year of his medical studies at Edinburgh University. Yet five years after those ‘incredibly dull’ lectures he was aboard HMS Beagle, charged with responsibility for mineralogical and geological investigations, reading Charles Lyell’s Principles of Geology (1830) with enthusiasm, planning his own geological textbook and writing of his fascination with geological study. This apparent about-face is not as remarkable or inexplicable as it appears, however, for in the passage quoted above Darwin is clear that his geological interests were not switched off by his experiences at Edinburgh, but continued despite those experiences: ‘I feel sure I was prepared for a philosophical treatment of the subject … I gloried in the progress of Geology’. When, therefore, Darwin’s mentor and friend John Stevens Henslow suggested to him that he turn his attention once more to geology, and arranged for Darwin to accompany Adam Sedgwick on a ‘geologizing’ expedition to Wales, he was planting a seed in fertile ground.

Darwin disliked the geological education he received at Edinburgh not because of the subject but the presentation: it was not geology that was ‘incredibly dull’ but the instruction he received. In addition, not only were the lectures dull, but the lecturer’s point of view was one which Darwin found unamenable. ‘Jameson’ was Robert Jameson (1774-1854), professor of natural history at Edinburgh and a passionate adherent of the Neptunist theory of rock formation – the theory that all rocks were precipitated from seawater and that the igneous processes invoked by the Plutonist school of geology were of no importance. Darwin had only to use his eyes – as on that day at Salisbury Crags – to know that this was nonsense. The ‘geological perspective’ he developed in spite of that early disheartening geology field-trip continued to inform his insights, bearing fruit not only in his own early geological publications but also subsequently, as he turned his attention to the biological realm.

Quote from: Charles Darwin, The Autobiography of Charles Darwin 1809-1882 (London: Collins, 1958), pp. 52-3. Available online at The Complete Work of Charles Darwin Online.

Image: Salisbury Crags and Arthur’s Seat, Edinburgh. Picture by Przemysław Graczyk, reproduced here under a Creative Commons License. [source]

For one week from 12 February 2009, the 200th anniversary of Charles Darwin’s birth, The Volcanism Blog will feature a volcano-related quote from Darwin each day.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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The Daily Volcano Quote: Charles Darwin on San Cristóbal 12 February 2009

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Charles Darwin. Portrait by George Richmond, c. 1838 (detail).

The Beagle sailed round Chatham Island, and anchored in several bays. One night I slept on shore, on a part of the island where some black cones — the former chimneys of the subterranean heated fluids — were extraordinarily numerous. From one small eminence, I counted sixty of these truncated hillocks, which were all surmounted by a more or less perfect crater. The greater number consisted merely of a ring of red scoriæ, or slags, cemented together: and their height above the plain of lava, was not more than from fifty to a hundred feet. From their regular form, they gave the country a workshop appearance, which strongly reminded me of those parts of Staffordshire where the great iron-foundries are most numerous.

Charles Darwin visited Chatham Island in the Galápagos, today known as San Cristóbal, between 17 and 23 September 1835, during the voyage of the Beagle. San Cristóbal is a low shield volcano which produces effusive lava flows from fissure eruptions. In this account Darwin is describing scoria or spatter cones, built up along the lines of the eruptive fissures from lava fragments thrown up during the eruptions. The account above is characteristic of Darwin: careful observation, precise description, and the use of a homely image – the landscape of the iron-founding areas of Staffordshire – to bring a strange and outlandish landscape vividly to life.

From Charles Darwin, Voyages of the Adventure and Beagle (London: Henry Colburn, 3 vols., 1839), vol. III, p. 455. Available online at The Complete Work of Charles Darwin Online.

For one week from 12 February 2009, the 200th anniversary of Charles Darwin’s birth, The Volcanism Blog will feature a volcano-related quote from Darwin each day.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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On this day: Kelut erupts, 1919 19 May 2008

Posted by admin in anniversaries, eruptions, Indonesia, Kelut, natural hazards.
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Mount Kelut (also known as Kelud), situated in the east of the island of Java, is one of the most active and hazardous volcanoes in Indonesia. Over the past six centuries the 1730m volcano has erupted at least thirty times and has been responsible for approximately 15,000 fatalities. On 19 May 1919 it was the site of one of the deadliest volcanic eruptions of the twentieth century, killing over 5100 people when water ejected from the crater lake formed lethal lahars that travelled nearly 40 kilometres and destroyed more than 100 villages.

The 1919 eruption is interesting not only for itself but for the response it generated. At the time Java was under Dutch colonial rule, and the Dutch authorities reacted to the disaster both institutionally, by establishing the forerunner of today’s Indonesian volcanological authority, and technologically, by creating a drainage system intended to manage the hazard posed by the crater lake.

The presence of a substantial crater lake has been the main reason why Kelut is a very lahar-prone volcano, but also significant are its deeply eroded flanks and abundance of loose sediment. During the 19 May 1919 eruption 38 million cubic metres of water was expelled from the crater lake, radiating out through the deep drainage channels and accumulating vast quantities of sediment and volcanic material to produce fast-moving lahars that inundated over 30 square kilometres of the surrounding countryside.

7 (1998), fig. 1.

Above: map of Kelut, showing the extent of the 1919 lahars. Adapted from Thouret et al, Bull. Volc., 59:7 (1998), fig. 1.

Even before the 1919 catastrophe the colonial authorities recognized the danger Kelut posed and had, in 1905, constructed a dyke intended to protect the nearby city of Blitar. The 1919 lahars, however, overwhelmed this construction. The Dutch response was to abandon the mitigation of lahars and concentrate instead on preventing them developing by enabling the drainage of the crater lake. The work took until 1926 to complete: a system of seven drainage tunnels was constructed, which reduced the volume of the lake by more than 2 million cubic metres, lowering the level by 50 metres. In 1951 the volcano erupted again, but the successful operation of the drainage system meant that little water was present in the crater and no lahars resulted. A second catastrophe had been averted.

The eruption itself, however, deepened the lake and destroyed the drainage tunnels. Only after another deadly eruption in 1966, in which more than 200 people died, was a new deeper tunnel excavated. The most recent large-scale eruption, in 1990, would certainly have been much more destructive to life and property had the crater lake not been largely drained.

Kelut’s most recent period of restlessness occurred in the autumn of 2007 and resulted in evacuations, although there was no large-scale eruptive activity. A lava dome which has grown since the autumn 2007 eruption now fills the crater lake site (see pictures Université Libre de Bruxelles here; h/t to commenter Hawkeye) and has overwhelmed the drainage inlets.

Information
Global Volcanism Program: Kelut – summary information for Kelut (0603-28=).
Kelud Volcano – information and analysis from the Université Libre de Bruxelles, Belgium (ULB). The volcanic lake specialists at ULB are currently collaborating with the Volcanological Survey of Indonesia in monitoring Kelut.
Le volcan Kelut – account of the 1919 eruption and a detailed history, with illustrations, of the various drainage systems built since to drain the crater lake (in French).

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