• Question: Could Inactive volcanoes (apparent to us) explode again?

    Asked by svputten312 to Rob on 20 Jun 2013.
    • Photo: Robert Woolfson

      Robert Woolfson answered on 20 Jun 2013:

      I am by no means an expert but here’s my best guess.

      A volcano erupts when the pressure of the molten rock (magma) below the surface of the volcano becomes too much and the magma goes streaming everywhere.

      If the volcano is extinct, then there is no magma left and it’s not going to explode as there’s nothing to cause an explosion.

      However, if a volcano is just dormant i.e. inactive then it’s a different matter. The magma is sitting below the surface and so it can still explode. Often you can predict an eruption because you can detect the changes in the magma pressure that start before a big eruption. However, volcanoes are very hard to predict.

      If you want a better answer, ask Matt. He’s the volcano specialist here.

Comments

  • Photo: Matt

    Matt commented on :

    Hi there svputten and Rob, just saw this question and I wouldn’t really change anything from Rob’s answer! It’s partly the pressure but also how quickly the chemical reactions happen. For instance, letting go of gas all in one go will cause an eruption, like letting go of a full balloon before you tie the end off. If you let go of the air slowly (or the gas escapes from the magma slowly) then the balloon will just make fart noises and not actually fly all over the room. Volcanoes fart all the time – and they stink too!