Some reminders from the National Park Service:
- Drownings are the number two cause of death in Olympic National Park (number one is car accidents). There is no need to leave the trail to approach the water or the waterfall itself to log this cache. Even very small amounts of water can present a drowning hazard.
- Please do not go off the established trail. The National Park Service is working hard to maintain the beauty and ecology of this area, and going off trail to create shortcuts hurts the ecosystem.
Waterfalls are an excellent place to view the erosional power of rivers and streams for several of their features. One of these features is called a plunge pool. Plunge pools are created when the force of the cascading water digs a hole at the base of the waterfall, creating a circular pond at the bottom that the stream then flows out of.
The size of a plunge pool is dependent on several variables, including the amount of water coming over the waterfall, whether it's a freefall or just a steep cliff slope, and the height of the waterfall. Pools can be quite large, like at Palouse Falls on the east side of Washington which has a pool that is about 400 feet wide.
Plunge pools can also cut into the cliff behind the waterfall. This process is called undercutting and can lead to the collapse of the entire cliff face, effectively moving the waterfall back.
To log this earthcache, you need to send me the answers to the following questions. Logs with the answers included will be removed. You do not need to leave the paved trail to answer these.
Questions:
1. Do you notice any undercutting behind the waterfall?
2. Is the waterfall a freefall, or does it "slide" down the rock?
- What impact do you think this has on the size of the plunge pool at this waterfall?
Image from the Wikipedia page about waterfalls.