Erosion can be caused by various forces, such as water and wind. At this site, the primary source of erosion is surface water runoff. Erosion is being fought by man and nature at this location. However, because of the soil's high angle of repose, the erosion here has exposed an interesting geologic history.
Angle of repose is the material's, soil in this case, steepest angle that can be maintained without slumping. To the north, the angle of repose is nearly 90 degrees, or vertical. To the west, the angle of repose is roughly 30 degrees. Yet it is the same soil at each location.
As you look from the road, you can see that there are at least two sources of water here, each eroding the soil in different ways. A culvert under the road releases water from the south side of the road to the north.
1) What has man done here to reduce erosion from culvert runoff?
Just downstream from here, a tree is fighting the erosion in a completely different way.
2) Why does nature's way seem to be working?
3) Why is the angle of repose nearly 90 degrees?
Just to the west of the culvert, at the second reference point, there is another source of erosion for this same eroded area. The water source here seems to be a spring and produced a completely different erosion pattern.
4) Describe the erosion pattern caused by the spring.
The cross section seen to the north of the culvert shows some geologic history. There is a band of material, of a different color than the surrounding material.
5) What is the different material in the band and why is it there?
Please send the answers to these questions to me in an email or caching message.