You will be able to view the effects of swirling water, flowing water, and falling water all from your vantage point on the observation deck. Bring binoculars if you want to get a closer look.
EARTHCACHE REQUIREMENTS
Each cacher must send his/her own answers BEFORE logging a find. Enjoy the journey (learning adventure) as well as the destination (smiley earned). Remember to take only pictures and leave only footprints. To get credit for this Earthcache, complete the following tasks:
OHIOPYLE FALLS
1. MESSAGE …. Observe and describe this waterfall. Include the height, width, magnitude of flow, and depth of pool at base of waterfall.
2. MESSAGE …. SWIRLING WATER ... a. Describe what you see that resulted from the water swirling over the rocks below you. ... b. There is something unusual in the rocks. What are they? How did they get there?
3. MESSAGE …. FLOWING WATER ... Describe what you see that resulted from the water flowing ... a. over the rocks in the river ... b. along the far side of the river ... c. along the side of the river below you.
4. MESSAGE …. FALLING WATER ... Describe what you see that resulted from the water falling over the rocks at the falls.
5. MESSAGE …. Based on your observations, which of the three (swirling/flowing/falling) is responsible for the greatest erosional impact on the landscape? Explain.
LOG …. Post a picture of you or your signature item at Ohiopyle Falls. This picture is your log signature for this location.
CUCUMBER FALLS
6. MESSAGE …. Observe and describe this waterfall. Include the height, width, magnitude of flow, and depth of pool at base of waterfall.
LOG …. Post a picture of you or your signature item at Cucumber Falls. This picture is your log signature for this location.
COMPARISON
7. MESSAGE …. a. Based on your observations, which waterfall is the highest? ... b. Based on the reading, which waterfall is the highest?
8. MESSAGE …. Based on your observations, which waterfall is responsible for the greatest erosional impact on the landscape? Explain.
OPTIONAL - Please respect the time and effort involved in creating this earthcache by adding A and B to your log.
A. JOURNEY OF THE MIND ... Science explains what we observe. Relate (in your own words) something you found interesting in the reading. This adds to your learning adventure and your log.
B. JOURNEY OF THE HEART ... Art shares our personal experience of what we see. Share something special you found on site, and why it is special to you. This is a memorable addition to your log and will make other hearts smile.
Journeys of Heart and Mind ...
Stories to Touch the Heart and Puzzles to Challenge the Mind / Rainbow Tree Story
THANK YOU Ben Monk for permission to share this earthcache.
MAGNITUDE OF FLOW
1st Magnitude - 2800 L/s
2nd Magnitude - 280 to 2800 L/s
3rd Magnitude - 28 to 280 L/s
4th Magnitude - 6.3 to 28 L/s
5th Magnitude - 0.63 to 6.3 L/s
6th Magnitude - 63 to 630 mL/s
7th Magnitude - 8 to 63 mL/s
8th Magnitude - 8 mL/s
0 Magnitude - no flow (sites of past/historic flow)
SWIRLING WATER
Due to the circular eddy currents, various size holes are ground into the rock. These holes range in size and shape depending on length of time and amount of water.
FLOWING WATER
Inside of the river bank meander is a sandy beach. Small sediments are deposited here, because the water slows down and can no longer carry them. Outside of the river bank meander is a rocky shelf. The water scours the outside of the river meander, because it moves faster here, and is therefore more erosive. This "scour zone" is where the park's most unique species of plants are found. It takes quite a tough plant to live a life in the scours. They must tolerate flooding in the spring and virtually no water for the rest of the year.
FALLING WATER
The nearly flat rocks you see are very resistant Homewood Sandstone ranging 40-60 feet thick. Near the base of the plunge pool is the Upper Mercer Coal and shale. When the water flows over the ledge, the churning motion of the water undercuts the less resistant shale and coal underneath the sandstone. Eventually the layer above collapses when the weight can no longer be supported. These are the large boulders visible at the base of the Ohiopyle Falls. Due to the power of moving water, they are transported along the river and are responsible for the rapids.
HOMEWOOD SANDSTONE
Homewood is very resistant sandstone that underlies both Cucumber and Ohiopyle Falls. This sandstone is 40-60 feet thick, and is acidic favoring the growth of acid-loving rhododendrons.
CUCUMBER FALLS
These falls are made from a shelf of Homewood Sandstone. There is a thick layer of coal underneath the sandstone. Since coal is softer than sandstone, it is more easily eroded, which accounts for the deep undercut below Cucumber Falls.
OHIOPYLE FALLS
The rocks you see are also Homewood Sandstone and are almost flat. Near the base of the plunge pool is the Upper Mercer Coal and shale. When the water flows over the ledge, the churning motion of the water undercuts the less resistant shale and coal underneath the sandstone. Eventually the layer above collapses when the weight can no longer be supported. These are the large boulders visible at the base of the falls. Due to the power of moving water, they are transported along the river and are responsible for the rapids.
WATERFALL ILLUSION
We expected observations of height, width, magnitude of flow, and depth of pool at base of waterfall to be different at each of the two waterfalls. We were surprised to learn that both waterfalls are actually at the same height. It is the other factors combined that give the illusion of the height difference. Pretty amazing!
RESOURCES
The Geology of Ohiopyle State Park and Ohiopyle Geology Tour ... available at the park office.
Ohiopyle Adventures with Kelly ... https://adventureswithkelly.com/2021/02/08/ohiopyle-geology-tour/
http://www.docs.dcnr.pa.gov/cs/groups/public/documents/document/dcnr_20032540.pdf
