A waterfall is a river or body of water that falls over a rocky ledge into a plunge pool beneath. A 'cascade' of water.
There are two important geologic processes that happen in the formation of a waterfall: 1) first, the wearing away of the earth (or erosion) at its highest point, and 2) the pressure of the falling water and traveling sediment at it's lowest point.
Across the earth's surface, streams flow over soft rock (like sandstone and limestone) and hard rock (like granite and basalt). It happens laterally (as a stream flows across the earth) and vertically (as the stream drops in a waterfall). Gravitational forces direct the water flow in both directions.
As the stream flows, it carries sediment. The sediment can be microscopic silt, pebbles, or even boulders. But over time, this sediment erodes stream beds (the physical bottom confine of a stream or river) in the soft rock until eventually, the stream's channel cuts so deep into the stream bed that only the harder rock remains. It is these jagged granite formations that become the cliffs and ledges where water starts to cascade over.
As the soft rock starts to wear away under the flow of water, a hard rock ledge forms over which the water falls. When the rocky ledge eventually breaks off, the underlying layer of soft rock erodes again until another hard edge is formed ... and the cycle repeats itself.
| CLICK to see how waterfalls form (51sec)
Although erosion is just one way that waterfalls form, another waterfall may form across a fault, or crack in the earth’s surface when an earthquake, landslide, glacier, or volcano disrupts a stream bed. Many of Haiti's waterfalls have been created this way.
| CLICK to see some popular waterfalls in Haiti
| CLICK to see cinematic views of large waterfalls (1:01:32min)
(We like to navigate these longer videos with the right arrow key so that with each click, we can see a new waterfall. Look at the many different geographic formations from which the water falls!)
| CLICK to see drone footage of 500 different waterfalls (3:44:16hrs)