According to tectonic theory, the surface of the Earth is made up of a patchwork of massive rigid plates, about 80km (50 miles) thick, which float in slow motion on top of the Earth's hot, pliable interior.

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This is the theory that life is not merely a surface scum which clings to the outside of planet Earth, but that living things, in the form of so-called extremophile bacteria which can tolerate infernal heat, penetrate several kilometres into the planet's interior.

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One theory is that the summer sun melts ice on the surface of the glacier which creates pools of water which then flow into moulins -- narrow tubular shafts in the glacier.

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