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Four of Iceland's Main Volcanoes Are All Preparing For Eruption (icelandmonitor.mbl.is)

Vulcanologists always watch Iceland carefully -- it's the one exposed place on the Mid-Atlantic Ridge, with 130 different volcanoes -- and something big may be brewing. Applehu Akbar writes: Now that four of Iceland's largest volcanoes are showing signs of impending eruption, the world may be in for another summer of ash. Katla, Hecla, Bárðarbunga and Grímsvötn have all had major activity in the past, including vast floods from melting glaciers, enough ash to ground aircraft over all of Europe, volumes of sulfur that have induced global nuclear winter for a decade at a time, and clouds of poisonous fluoride gas. When the mountains of Iceland speak, the whole world listens.
Eruptions are already overdue for both Hekla and Katla -- Hekla's magma chamber has filled up, and Katla last erupted in 1918. "The Katla eruption would lead to the melting of the Mýrdalsjökull glacier, resulting in a glacial flood," reports Tech Times, "likely to hit areas where large crowds are found at any given point of time, especially the black sand beaches of Sólheimasandur and the village of Vik in Southern Iceland."

7 of 136 comments (clear)

  1. Scale by SteveAstro · · Score: 4, Informative

    From WikiPedia

    The flood discharge at the peak of an eruption in 1755 has been estimated at 200,000–400,000 m3/s (7.1-14.1 million cu ft/sec), comparable to the combined average discharge of the Amazon, Mississippi, Nile, and Yangtze rivers (about 266,000 m3/s (9.4 million cu ft/sec)).

    THAT is a lot of warm water.

    1. Re:Scale by Rei · · Score: 4, Informative

      Not in historic times there haven't been. The fact that Iceland's volcanoes launch these sort of superfloods once every several hundred years is something not seen elsewhere in the world. This canyon, for example:

      Ásbyrgi

      is under 10k years old. It was carved primarily by just one or two superflood events, but the flow rate estimates (based on the size of the boulders thrown around) are as high as 900000 cubic meters per second. In Icelandic, if a flood is less than 45000 cubic meters per second it's defined as "non-catastrophic". By comparison, the Niagara River at Niagara falls is 2400 cubic meters per second.

      The very word for this type of flood is Icelandic - "jökulhlaup". Literally "glacial run". And the name for the sediment deposits they leave behind is also Icelandic in origin - "Sandur" (literally "sand").

      --
      I spent the evening flickering into your darkness.
    2. Re:Scale by Rei · · Score: 3, Informative

      I guess it depends on the situation. But the three main ways they tell if there's been a small jökulhlaup are a) monitoring flow rates, b) monitoring electrical conductivity of the water, and c) monitoring water temperature. Rising flow, EC and temperature are all signs of jökulhlaup. You also often get a sulfrous smell to the water and reduced clarity.

      --
      I spent the evening flickering into your darkness.
  2. Re: Giaa to the rescue! by Rei · · Score: 4, Informative

    I'll take volcanoes any day over heat. :) And monsoons... what, you mean precipitation? Yeah, I think we've got that covered ;) Mýrdalsjökull (Katla's glacier), along with neighboring Eyjafjallajökull, and further away Vatnajökull, are the wettest places in Europe, with over 10 meters of precipitation per year (although we don't have the record for wettest inhabited area... because living on top of a glacier on top of an active volcano would be pretty damned stupid ;) ).

    --
    I spent the evening flickering into your darkness.
  3. Re:Otherwise Known As A Jökulhlaup by Rei · · Score: 4, Informative

    The irony is that the French Revolution led to the Napoleonic Wars, which Denmark losing Norway, which led to them clamping down on their other strikecolonies/striketerritories, which led to resentment, the Icelandic independence movement, and ultimately independence from Denmark.

    Yeah, Laki was really horrific. It's hard for polar volcanoes to affect the climate like equatorial ones do, but the scale of the amount of gas released was nonetheless so great that the Mississippi froze at New Orleans. The African and Indian monsoon failed, leading to severe famine in Egypt; 6 million people died. Benjamin Franklin was the first person to correctly attribute the cause of the weather to an Icelandic volcano eruption (although he incorrectly stated it as Hekla, which seems to have been the only Icelandic volcano that people in that timeperiod seemed to know, due to its habit of dusting mainland Europe with ash ;) )

    Once every 100-200 years Iceland has some truly catastrophic eruption. Laki has had two since the settlement period. Askja, Katla, and Hekla are other sources. Barðarbunga is a real giant (largest lava eruption of the Holocene), but it hasn't had any catastropic eruptions in a while. It's still quaking up a storm since it's last "little" one (little by its standards, still bigger (both volume and flow rate) than any eruption Mauna Loa has ever had).

    --
    I spent the evening flickering into your darkness.
  4. Re:Giaa to the rescue! by stjobe · · Score: 5, Informative

    Volcanoes [...] let out more greenhouse gases than all human created machinery - from cars to planes to everything that emits carbon dioxide

    Eh, no: "Volcanoes emit around 0.3 billion tonnes of CO2 per year. This is about 1% of human CO2 emissions which is around 29 billion tonnes per year."

    --
    "Total destruction the only solution" - Bob Marley
  5. Re: Giaa to the rescue! by Anonymous Coward · · Score: 2, Informative

    > Here in the UK people living in flood plains get flooded, who
    > would have expected that eh? And then they go complaining
    > to the government. That's mostly as bad as it gets.

    Many years ago, local governments would dredge river channels every so often, so they wouldn't flood. Good. Then Britain joined the EU. Along came unelected Eurocrats, who imposed ridiculously punitive/expensive standards regarding the disposal of the dredged up mud/silt. Result...
    * local authorities couldn't afford to dredge river channels
    * river channels silted up
    * rivers flooded

    Well... like... duhhhh. To add insult to injury, the flooding was wrongly blamed on global warming. It was crap like this that contributed to the Brexit vote result.

    No the UK government cut the funding. Nothing to do with the EU.