The coordinates will take to you the oxbow of the White River near the Broad Ripple park. Since this is in a city park, this Earthcache is not available after dark.
Broad Ripple Park is a 61-acre park on the northeast side of Indianapolis, bordering the White River. Broad Ripple Park facilities include an outdoor swimming pool, tennis courts, baseball diamond, multi-use athletic fields, playground, picnic shelters and areas, a viewing platform over the White River, a bark park, a wooded preserve, a walking/jogging/running/bicycling and fitness path, and a boat ramp to the White River.
The park has a rich history in the community as the home of a 1920s amusement park, carousel (now at the Indianapolis Children’s Museum), a steam locomotive (now at the Transportation Museum in Noblesville), and as the location of the Olympic tryouts for swimming in 1924 and 1952.
Meander Formation
Meanders form due to the greater volume of water carried by the river in lowland areas without much change in elevations, which in return results in sideways erosion being more dominant than vertical erosion. This will cause the channel to cut into its banks forming meanders.
1. Water will flow faster on the outer bend of the river where the channel is deeper and there is less friction. This is due to water being flung towards the outer bend as it flows around the meander. This will cause greater erosion and deepen the channel. This sideways erosion results in undercutting of the river bank and the formation of a steep sided river cliff.
2. The inner bend water is slower and will deposit materials in a shallower channel. This increased friction slows the water flow and will have even more depositing. Material builds up on the inner bend; this is called a slip-off slope.
A meander will gradually change its shape and migrate across the floodplain. Meander bends becomes pronounced due to further sideways erosion and eventually an oxbow lake may form.
Oxbow Lake formation
- As the outer banks of a meander continue to be eroded, the neck of the meander becomes narrow and narrower.
- Eventually the two outer bends meet and the river cuts through the neck of the meander. The water now takes its shortest route rather than flowing around the bend.
- Deposition gradually seals off the old meander bend forming a new straighter river channel.
- Due to deposition the old meander bend is left isolated from the main channel as an ox-bow lake.
- Over time this feature may fill up with sediment and may gradually dry up (except for periods of heavy rain). When the water dries up, the feature left behind is known as a meander scar.
To log this Earthcache, send me the follow answers:
- Explain the differences in the appearance of the inner bend and outer bend of the White River oxbow.
- What signs of erosion are evident? What signs of depositing are seen?
- Post a picture of yourself (face not required) or a personal item at the oxbow.