Power at the Base – The Plunge Pool of Upper Chedoke Falls
Welcome to Upper Chedoke Falls, also known as Scenic Falls, located along the Niagara Escarpment in Hamilton, Ontario.
Upper Chedoke Falls is a ribbon waterfall on Chedoke Creek. The waterfall is approximately 15–18 metres tall and flows year-round over the escarpment rocks.
This waterfall is hidden inside a steep escarpment gorge surrounded by limestone and dolostone cliffs, mature forest, and eroded valley walls. The creek and waterfall have been partially altered by urban development, but the falls still continue to shape the landscape naturally through erosion.
What Is a Plunge Pool?
A plunge pool is a deep bowl-shaped depression found at the bottom of a waterfall. It forms when falling water crashes into the rock below with tremendous force.
The water does not simply hit the bottom and stop. Instead, it swirls in circles, carrying sand, gravel, and rocks. These rocks act like natural grinding tools that slowly wear away the stream bed.
Over thousands of years, this erosion carves out a deeper and wider hole called a plunge pool.
At Upper Chedoke Falls, the falling water constantly strikes the base of the escarpment. The softer or fractured rock near the bottom erodes faster than the stronger rock above. This process helps create:
- an undercut behind the waterfall,
- steep rock walls,
- broken rock fragments,
- and the plunge pool itself.
Plunge pools are important geological features because they show active erosion in action. They also help waterfalls slowly retreat upstream over time as rock collapses from beneath the ledge.
🔎 Questions
To log this EarthCache, carefully observe the waterfall and plunge pool area. Using your observations and the information provided on this cache page, email me the answers to the following questions.
- Describe the shape of the plunge pool. Does it appear round, oval, deep, shallow, smooth, rocky, or uneven?
- Look at the rocks near the bottom of the waterfall. What evidence do you see that erosion is happening?
- Why does the plunge pool form at the bottom of the waterfall instead of at the top?
- Compare the rock near the top of the waterfall to the rock near the bottom. Which area looks more worn or broken? Why?
- Based on your observations, do you think the plunge pool is still forming today? Explain your answer.
- MANDATORY: Post a picture of you or a personal item with the plunge pool in the background
Congratulations to boekmeisje on the FTF!