Earthflows contain less than 20 per cent water. Slower and more viscous than mudfows, they often follow distinct flow tracks with bulging lobes at the toe marking the final resting point. The 1966 Aberfan disaster (which, arguably, might better be described as a mudflow given the rapidity of the event) is a much-quoted example, the lessons from which have enabled the mining industry to stabilise other colliery spoil tips by drainage and maintenance of height and slope.