{"id":1308,"date":"2014-08-26T12:32:37","date_gmt":"2014-08-26T11:32:37","guid":{"rendered":"http:\/\/all-geo.org\/volcan01010\/?p=1308"},"modified":"2014-08-26T12:32:37","modified_gmt":"2014-08-26T11:32:37","slug":"bardarbunga-turning-dettifoss-into-niagara-falls","status":"publish","type":"post","link":"https:\/\/all-geo.org\/volcan01010\/2014\/08\/bardarbunga-turning-dettifoss-into-niagara-falls\/","title":{"rendered":"B\u00e1r\u00f0arbunga – turning Dettifoss into Niagara Falls"},"content":{"rendered":"

While international concern about an eruption at B\u00e1r\u00f0arbunga is focussed on flight disruption, a j\u00f6kulhlaup<\/a> (meltwater flood) is the most destructive potential outcome of a subglacial eruption. It would travel north from the glacier along the J\u00f6kuls\u00e1 \u00e1 Fj\u00f6llum river, and for this reason roads have been closed<\/a> in the area. Edwin Baynes is a PhD student at Edinburgh University who studies past j\u00f6kulhlaups in this area. In this guest post, he puts such a potential flood in context.<\/p><\/blockquote>\n

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Turning Dettifoss into Niagara Falls<\/h3>\n

An Icelandic geophysicist, Magn\u00fas Tumi Gu\u00f0mundsson, has predicted that if a subglacial eruption were to occur at B\u00e1r\u00f0arbunga, the meltwaters could increase the discharge in the J\u00f6kuls\u00e1 \u00e1 Fj\u00f6llum river by 10 or 20 times<\/a> (to 2,000 – 4,000 m3<\/sup> s-1<\/sup>). He describes such a flood as ‘not catastrophic<\/em>‘ because it is smaller than the j\u00f6kulhlaups<\/a> caused by the 1996 Gj\u00e1lp eruption (45,000 m3<\/sup> s-1<\/sup>), which washed away the Skei\u00f0ar\u00e1sandur bridge in South Iceland, or the estimated discharge for the Katla 1918 flood<\/a> (300,000 m3<\/sup> s-1<\/sup>). It is still very serious, however, and has potential to inundate the landscape and destroy important infrastructure such as bridges and farms. The map below shows the areas most likely to be affected.<\/p>\n

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Area most likely to be affected by j\u00f6kulhlaup following subglacial eruption at B\u00e1r\u00f0arbunga. Published by Morgunbla\u00f0i\u00f0 – click image to see original article.<\/p><\/div>\n

J\u00f6kuls\u00e1 a Fj\u00f6llum contains some pretty impressive waterfalls, the most notable of which is Dettifoss. With a vertical drop of around 50 m and a peak summer discharge of 300-400 m3<\/sup>s-1<\/sup>, it is reputed to be \u2018Europe\u2019s most powerful waterfall<\/a><\/span><\/span>\u2019. Sci-fi fans may recognise it from the start of Prometheus, much of which was filmed in Iceland<\/a><\/span><\/span>.<\/p>\n