Water is one of the Earth's more powerful landscapers. You would
be hard pressed to find a feature on Earth's surface that hasn't
been shaped by water in some form or fashion. Yet, it is also a
remarkably subtle landscaper, taking hundreds, thousands, even
millions of years to produce many of the geologic features we see
today.
Waterfalls are a popular example of how water has shaped the
Earth. Varying in shape, structure, and magnitude, they can create
amazing scenic vistas while demonstrating how active our Earth is
in real time. Their formation alone is an example of the power of
water.
Waterfalls form when water flows over a ledge, or step, in the
rock bed underneath. The speed and amount of water as it reaches
this point will affect the position and shape of the waterfall. If
the underlying rock is soft enough, the waterfall will slowly
recede over time. If the underlying rock is hard, recession may not
occur without a large volume of water and sediment flowing over the
edge.
Ponds can form at the bottom of the waterfall if the rock layers
at that point are soft as well. The force of the water as it hits
the bottom carves away the softer rock, slowly creating what is
called a plunge pool. Sediment and rocks moved around by the force
of water will further carve away the underlying rock.
Another feature that can form as a result of softer rock is an
overhang. This happens when the rock at the top of the waterfall is
hard, but it lies on top of a much softer rock. As the water hits
the water in the plunge pool, some of the water will splash back
against the wall, slowly carving away the soft rock until an
overhang develops. If enough soft rock is worn away over time, then
the hard rock located above my begin to suffer enough stress that
it eventually will break, causing the waterfall to recede even
further.
Oftentimes, you will find waterfalls surrounded by canyons or
gorges. When this is found, it usually means that the waterfall has
been active for a long time. The canyon or gorge is formed as a
result of the waterfall slowly receding during the course of it's
lifetime.
If you observe enough waterfalls, you'll begin to notice just
how varied they can be, and not just because of the amount of water
or how tall they are. There are different types of waterfalls,
determined by how the water flows through the system.
Common
waterfall classifications (with pictures).
- Block - Water from a wide river or stream drops over a
ledge forming what appears to be a "sheet" of water.
- Cascade - Water flows down a series of steps or
stages.
- Cataract - Large, powerful, and water flows with a lot
of force.
- Fan - Water falls through a relatively narrow crest and
spreads out and becomes wider as it descends.
- Horsetail - Water descends down, remaining in contact
with the surface rock most of the time.
- Plunge - Water descends vertically without contact with
the surface rock.
- Punchbowl - Water falls through a constricted area and
descends down into a pool of water.
- Segmented - Pieces of land segment the river causing the
water to split in separate sections as it descends.
- Tiered - Separate consecutive waterfalls in close
proximity that are close enough that they are generally seen as one
long waterfall.
- Multi-step - A series of waterfalls one after another of
roughly the same size each with its own sunken plunge pool. Not to
be confused with Tiered, which don't have separate plung
pools.
It is not uncommon to find waterfalls that meet the descriptions
of more than one classification. In such instances, a waterfall
would be classified as both. For example, the last step of a
Cascade waterfall may include a Plunge waterfall, thus classifying
it as a Cascade Plunge.
Cave Spring Falls
The waterfall in Cave Springs originally received water from
three tributaries. One was a former lake that has since disappeared
due to the Kansas City flood in the 1950's and local construction.
The following aerial photo was taken in 1931. The mentioned lake is
seen in the lower left corner. The current Nature Center would be
in the lower right. The road on the right site is nearby Gregory
Blvd. Notice the perfectly round circles? Those are the greens of
the old golf course formerly located here:
Another source was the nearby cave (located at N 38° 59.580 W
094° 29.039). This cave used to supply a considerable amount of
water up until the 1940's, when the construction of a nearby church
resulted in the discovery and subsequent plugging of a nearby
underground spring. In 1928, it was reported that the cave spring
pumped out about one million gallons of water a day. The photo
below shows water coming out of the cave in the 1930's:
A third source of water was another nearby creek. This creek
actually fed into the same source stream that traveled from the
lake to the waterfall, adding to the water in that stream. Both
this stream, and the stream from the nearby cave, converged into
the single stream the provides water for the waterfall.
To Complete this Earthcache:
To complete this Earthcache, you will need several supplies. Make
sure to bring with you a camera, measuring tape (or yardstick), a
timer (or watch with a seconds hand), and a bucket or some other
wide mouth item to measure water. Don't forget your GPSr. Send
answers to #'s 1 and 2 to the cache owner. Post # 3 with your cache
log.
1. Using the above classifications, identify what classification of
waterfall this is.
2. Measure the amount of water flowing over the edge of the
waterfall (see instructions below). This can be done in liters/hr,
liters/day, gallons/hr, or gallons/day. Make sure to specify what
units of measure you are using.
3. Take a photo of yourself with the waterfall in the view.
Optional # 3: Take a photo of yourself at the nearby cave which
helps supply water to the waterfall.
NOTE: Taking a photo is part of the original intended
requirements. With the amount of camera phones out there, most
people can get a quick photo. The photos are helping in documenting
the waterfall, but if you are unable to obtain a photo or need help
with getting the photo posted, let me know in your e-mail. I won't
delete your log over it, but I'd hate to think that a bunch of
people stop taking photos because of this.
Instructions for measuring water flow:
The more accurate method for you to measure the water flow is to
measure how long it takes to collect a measured amount of water.
This is easiest to do with a bucket. Before you go out to do this
cache, make sure you know how much water the bucket can hold. If
need be, measure out a set amount of water, and pour it into the
bucket until close to full, then mark the water level with a marker
or tape. When setting this up, I marked off a bucket at the 4 Liter
point.
Once you have the necessary supplies, you have permission from
the park manager to walk right up to the waterfall to make your
measurements. First, get your timer ready. When ready, place the
bucket under a point in the waterfall and time how long it takes to
fill the bucket (or reach whatever measurement mark you previously
determined). Perform this test at least twice and average, then
record your times.
Next, measure the width of the bucket at the point you marked
earlier. Record the width.
It is easy to get the wrong measurement for how wide the
waterfall is at the point before the water starts to drop.
To keep measurements more accurate across all measurements, I will
provide my measurement, which was 30 inches across.
Now for some math:
- A = The amount of water in the bucket (my example was 4
Liters).
- B = The time it takes to fill the bucket with the amount of
water in A.
- C = The width of the bucket
- D = The amount of times B goes into 1 minute.
To calculate the amount of water:
- Multiply A times D.
- Divide 30 inches by C.
- Multiply these two numbers together to get the amount of water
that flows over the waterfall in one minute.
1 Liter of water equals .26 gallons of water.
1 Gallon of water equals 3.79 liters of water.
Park Information
Park hours:
- Park open daily, year round, from 9AM - Sunset
- Nature Center open Tuesday - Friday, 10 AM - 4 PM, Saturday by
appointment
A map of the site is posted in the bulletin board near the
Nature Center. Maps to take with you can be found inside the Nature
Center. The waterfall is marked on the map. Please approach the
waterfall from the West for the easiest approach.
Check out the Nature Center to find some cool information about
the history of Cave Springs, including some important historical
figures who have visited the Cave Springs area in the past.
Measurements taken while completing this Earthcache are being
recorded for the park. These measurements will be used to compare
the current rate of flow with the known flow rate taken in the
1930's for comparison. As such, please try to submit the date and
time you took your measurements. The park manager informed me that
he has seen the flow rate vary and is quite interested to see what
numbers come out of this earthcache.
Sources:
