🟩 SECTION 2: THE FEATURES OF A WATERFALL

What is a plunge pool?

A plunge pool is a hollow at the base of a waterfall.

It develops through the force of falling water and the erosion caused by rock fragments.

As water falls, it strikes the base and helps deepen the hollow.

Remember: The plunge pool is found at the foot of the waterfall.

How does a plunge pool form?

1. Water falls from the waterfall onto the riverbed below.

2. The force of the falling water erodes the rock.

3. Rock fragments carried by the water help wear away the riverbed.

4. A hollow develops at the base of the waterfall.

5. Continued erosion can deepen the hollow, forming a plunge pool.

Important: The plunge pool is associated with erosion at the base of a waterfall.

What is an overhang in waterfall formation?

An overhang is a section of harder rock that projects outward above softer rock that has been eroded more quickly.

The softer rock beneath the harder rock is worn away, leaving the harder rock unsupported.

Eventually, the overhanging rock may collapse.

How does an overhang develop at a waterfall?

1. A waterfall flows over harder rock.

2. Softer rock beneath or behind the harder rock is eroded more quickly.

3. The softer rock is worn away, creating an undercut section.

4. The harder rock projects outward above the undercut area.

5. An overhang develops.

6. The overhang may eventually collapse when it is no longer sufficiently supported.

Memory tip: Softer rock erodes first, leaving harder rock projecting outward.

What are fallen rocks in waterfall formation, and how do they contribute to erosion?

Fallen rocks are pieces of rock that have broken away and collapsed from the waterfall area.

When these rocks are moved by the water, they can strike and scrape the riverbed, contributing to erosion.

This helps deepen the plunge pool and contributes to the continued retreat of the waterfall.