HOW WATERFALLS FORM
Over time, the power of flowing water can gouge channels out of the land and shape solid rock
WORDS SCOTT DUTFIELD
Waterfalls form through a natural process called erosion, and different layers of rock are eroded at different rates. Harder rock, such as granite, erodes much more slowly than softer stone such as sandstone. Over the course of thousands – if not millions – of years, a watercourse such as a river will naturally erode the bedrock it flows over. If the bedrock is made of a hard rock top layer with soft layers underneath, the water will eventually cut through the hard rock and meet the soft rock below. It then erodes the softer rock at a much faster rate than the top layer, which ultimately carves out a cliff-like drop for the water to cascade over.