• Question: What created convection currents in the earths mantle?

    Asked by Kai&Olls to Anna, George, Jodi, Rob, Stefan on 19 Nov 2014.
    • Photo: Stefan Lines

      Stefan Lines answered on 19 Nov 2014:

      Hi Kai&Olls. Good question. Since the Earths mantle acts as a viscous (sticky) fluid even though it is solid, it is able to exhibit convection. I think it works like normal convection where hot areas move to cooler areas…and the cooler area sinks and it warmed up again (as it changes density). I imagine the hot dense core of our Earth donates the heat to Mantle, which is then lost through the crust (cooling). When it cools, the density increases and the material sinks back to the core to be reheated.

    • Photo: Anna Scaife

      Anna Scaife answered on 19 Nov 2014:

      Hey guys – Convection is caused by differences in temperature: heat flows from hot to cold. Different types of material and different densities of material transfer heat at different rates, so you get particular patterns in the heat flow which we call currents. The convection currents in the Earth’s mantle come from heat in the outer core being transferred up to the cooler surface of the mantle.

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