Understanding Waterfalls Formation

What is the primary reason waterfalls form in the upper reaches of rivers?

• The presence of abundant vegetation

• The presence of a hard rock layer over a soft rock layer

• The river's high salt content

• The river's proximity to the ocean

On Mohs' scale of hardness, where does lava rank?

• 10

• 3

• 7

• 5

What is the term for the pool at the base of a waterfall?

• Erosion pool

• Water basin

• Riverbed

• Plunge pool

What happens to the overhanging hard rock as the soft rock beneath it erodes?

• It becomes more stable

• It collapses and retreats

• It becomes softer

• It expands

Which of the following is NOT a waterfall formed at the end of a lava flow from Mount Ruapehu?

• Victoria Falls

• Tawhai Falls

• Mangawhero Falls

• Taranaki Falls