A waterfall occurs where a river flows over a vertical slope.
Waterfalls are a feature of erosion.
An example of a waterfall can be seen at Powerscourt, County Wicklow.
Formation of a Waterfall
River flows over an area where hard rock lies on top of an area of soft rock.
The river erodes the soft rock faster. This creates a vertical drop where the hard rock and soft rock meet. This drop is called a waterfall.
At the base, a plunge pool forms due to the force of falling water along with its load swirling around at the base which wears away the base by abrasion.
The rock above the plunge pool is undercut and left hanging. It eventually collapses into the plunge pool below. As this process continues, the waterfall slowly erodes its way upstream.
