Sitting on top of a volcano

Steam vents at the Craters of the Moon, Taupo

Here in New Zealand we are perched on a land mass where two continental plates collide. Below us, the friction and fracturing create tremendous heat and release the molten rock that lies beneath the crust.

When that magma contacts groundwater, the steam finds its way up to the surface in the form of vents and geysers and bubbling hot springs. They make up one of the tourist attractions around the two big islands. The Earth here shudders and moves. A year ago, hundreds of people were killed in Christchurch on the South Island when a major earthquake struck.