• Question: how was lava made

    Asked by maseehullah to Louise, Michaela, Sian, Steve, Yvette on 17 Jun 2010 in Categories: . This question was also asked by siddiq.
    • Photo: Steven Kiddle

      Steven Kiddle answered on 16 Jun 2010:

      Lava is made in the inside of the earth. We live on solid rock known as the crust, these also form tectonic plates. underneath the crust is molten rock, that is rock heated to such extreme temperatures that it melts. This is where lava is made, volcanoes are when this molten rock escapes through the the crust.

    • Photo: Michaela Livingstone

      Michaela Livingstone answered on 16 Jun 2010:

      Lava is very hot rock. When water is very cold it’s ice, which is solid, and then it heats up it turns to liquid (as we usually know it) and then when it gets even hotter it turns to a gas (steam). So lava is similarily rock that has got so hot that it’s turned to liquid, it’s just that it has to be hotter than water before it’s a liquid. Some chemicals, like nitrogen for example have to be very very very very cold to be a liquid, as usually it’s a gas. Different chemicals have different temperature where they melt (ie turning to liquid) and boil (turn to gas).

    • Photo: Louise Johnson

      Louise Johnson answered on 16 Jun 2010:

      This isn’t my area, sorry! I know that it’s only called lava when it comes out of a volcano, and while it’s still in the ground it’s magma. The earth’s core is hot enough to melt rocks – I think heat gets through more easily in some areas than others which is why magma can build up under volcanoes.

    • Photo: Yvette Wilson

      Yvette Wilson answered on 17 Jun 2010:

      lava is melted rock (at temps of about 700 degrees!) from the centre of the earth. It’s thick or thin depending on the chemical composition.

Comments

  • Photo: cewwen

    cewwen commented on :

    How come the lava isn’t strong enough to melt/destroy all of the rock on the outside of the volcanoes?

    • Photo: Michaela

      Michaela commented on :

      Rocks of different types ‘melt’ at different temperatures too, lava forms basalt rock that is a lot ‘weaker’ in this sense that most other types of rock, so that’s one reason why. The other may just be that by the time it gets out of the ground, where it’s being kept so hot, it cools down to the point where it’s still molten enough to move down the side of the volcano, but because the volcano rock is quite cold itself, the lava never then gets hot enough to melt that rock.

      You’ll need to find a geologist though because I honestly don’t know for sure. Good question though!