❓ why
Why do waterfall pools and river gorges often have steep rock walls?
GeographyWaterfalls
Quick Answer
They form because fast water erodes downward and backward, while the surrounding rock stays more resistant. Repeated erosion leaves narrow valleys with steep sides.
The Full Story
A powerful waterfall can deepen a valley very quickly compared with the wider river upstream. The rushing water excavates the base and destabilizes the surrounding rock, causing pieces to collapse. Over time, this creates a narrow gorge with near-vertical walls. In places like Niagara Gorge, the steep walls mark the path of the waterfall as it retreated upstream. Gorges are therefore a visible record of long-term erosion by moving water.
Key Facts
1.Waterfalls can carve gorges as they retreat
2.Collapsing rock helps keep walls steep
3.Niagara Gorge records past waterfall movement
YouTube Angle
Suggested video title for this topic:
"The canyon a waterfall leaves behind"