RAPID Bifurcation EarthCache

To log this Earth Cache, E-mail or Message me the answers to the following questions. The answers can be found in the below text and/or by visual observation at the posted coordinates.

1) In your email/message, note RAPID Bifurcation, GC9V7R7, and how many in your group.
2) In your option, is this an example of a TEMPORARY or SEMI-PERMANENT bifurcation?
3) Does this appear to be an STABLE or UNSTABLE bifurcation?
4) While standing at the bank of the creek, you should see a man made object in the center of the stream, may be submerged. ESTIMATE the WIDTH (Up and down stream) of this object. BONUS: Let me know your guess of what it is/was.

OPTIONAL: Post a picture of yourself at the location.

What is a Bifurcation

River (Creek) bifurcation (from Latin: furca, fork) occurs when a river (creek) flowing in a single brantch separates into two or more separate branches (called distributaries) which then continue downstream. Some rivers (creeks) form complex networks of distributaries, typically in their deltas. If the streams eventually merge again or empty into the same body of water, then the bifurcation forms a river island.

River (creek) bifurcation may be TEMPORARY or SEMI-PERMANENT, depending on the strength of the material that is dividing the two distributaries. For example, a mid-stream island of soil or silt in a delta is most likely temporary, due to low material strength. A location where a river (creek) divides around an area with packed soil and well established trees, or a mountain, may be more lasting as a result of higher material strength and resistance to weathering and erosion. A bifurcation may also be man-made, for example when two streams are separated by a long bridge pier.

River (creek) bifurcation commonly occurs in meandering and braided rivers, but is not uncommon in other types of rivers. In meandering rivers, bifurcations are often unstable in their configuration, and usually result in channel change in course. The stability of bifurcation is dependent on the rate of flow of the river (creek) upstream as well as the sediment transport of the upper reaches of the branches just after bifurcation occurs. The evolution of bifurcation is highly dependent on the discharge of the river(creek) upstream of the bifurcation.

• UNSTABLE bifurcations are bifurcations in which only one channel continualy receives water.
• STABLE bifurcations are bifurcations in which both channels continualy receive water.

While there does not appear to be a way to know for sure how this example came to be, there are clues here. As previously shown, it is not uncommon for a man made object to cause a bifurcation. We also know there was a major flood here in 1972. This example gives the the chance to work through the dynamics of the visual evidence and come to your own conclusion.

RAPID:

- Earth Caches are lightweight, simple examples and definitions of Earth features. The questions are designed to show your attention to and attendance at the feature. These questions are intended to be answerable by teens (and perhaps younger children) and not make one feel they just finished a college exam.

- Creek is a tributary of the Cheyenne River, approximately 86 mi (138 km) long. The creek's name comes from the Sioux Indians of the area, for the many rapids in the stream. It rises in the Black Hills National Forest west of Rapid City. It flows east, through Rapid City, ending at a confluence with the Cheyenne River. Rapid creek is entirely inside of the state of South Dakota.

- City, South Dakota, USA is the location where this grouping of these Earth caches are located.