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Explode or Flow? Global Warming or Volcanic Winter?

  • 07-05-2013 10:02am
    Moderators, Category Moderators, Science, Health & Environment Moderators, Society & Culture Moderators Posts: 47,029 mod Black Swan

    Viscosity of volcano magma has been a major contributing factor associated with whether a volcano explodes or flows during an eruption. The greater the degree of viscosity, the greater resistance to flow. Magmas with high silica content (silicon dioxide SiO2) have greater viscosities than those with low silica; e.g., high silica volcanoes are more likely to plug, build up pressure, and explode.

    The Kilauea volcano located on Hawaii Island ("Big Island") is active, and has been experiencing an intermittent fissure eruption since 3 January 1983. It has a low silica content, consequently is more likely to flow than explode. Its lava lake can be visited at the 1247 m summit by tourists. See temporary HT thermal cam view of volcano vent.

    Similar to the Richter magnitude scale for earthquakes, volcanoes can be measured against a 0-to-8 Volcanic Explosivity Index. A VEI of 4 or above is considered a large explosion, typically associated with high silica magma content.

    Mount St Helens experienced a VEI=5 "very large" explosive eruption 18 May 1980, where 3.7 billion cubic yards volume had been removed by the explosions. When compared with the Hawaiian Kilauea's low silica content, Mount St Helens had relatively high silica content in its magma.

    In addition to worrying about Global Warming, if planet earth was to experience a Mount Toba-like super-eruption, which took place at the Indonesian island of Sumatra about 75,000 years ago, we may experience a Volcanic Winter (although it has been recently debated).

    So if you don't want to blow your top, cut back on the silica in your diet.

    Your thoughts?