A creek or river scour channel is an area where the water has moved rocks, dirt, and other debris out of the way, all the way down to the bedrock. While standing at ground zero the water height above creek bed below, was around 10-15 feet high with the heavy spring rains of 2013. Evidence of this flash flood can still be seen today as you walk along the trail here. The best are to see debris still in trees is close to parking waypoints 1 and 2, along the trail. There are several spots with debris at least 10-15 feet high.
Erosion
Erosion is the process by which soil and rock are removed from the Earth's surface by natural processes such as wind or water flow, and then transported and deposited in other locations.
In this particular area at GZ, Water has caused most of the Erosion here. Springs are both caused by erosion and causes of erosion.
Types of Erosion:
Splash Erosion: Small soil particles are detached and sent airborne through the impact of raindrops on soil.
Sheet Erosion: Raindrops break apart the soil structure and it's moved down-slope by water that flows overland as a sheet rather than definitive channels. This occurs frequently during cloud bursts.
Rill Erosion: This process develops small, short-lived, concentrated flow paths. These paths create a sediment source and delivery system for hill-slope erosion. Areas where precipitation rates exceed soil infiltration rates are more prone to this type of erosion.
Gully Erosion: Water flows in narrow channels during or directly following heavy rains or melting snow. The gullies can erode to considerable depths.
Valley or Stream Erosion: Continual water flow alongside land (along a linear feature) creates this type of erosion. It extends downward, deepening a valley, and head-ward, extending the valley into the hillside. This occurs most frequently in times of flooding.
Bank Erosion: Over time, banks of rivers and streams are naturally worn down.
Freezing and thawing: Cold weather causes water trapped in tiny rock cracks to freeze and expand, breaking the rock into several pieces.
**Logging requirements**
DO NOT POST ANSWERS IN YOUR LOG.
Send the following answers to me via email.
- The text "GC52VJY Scour" on the first line
- How many levels of bedrock shelves can be seen while looking “downstream” from ground zero?
- Are the bedrock shelves rough with mostly jagged areas or smooth with some pits?
- How far does this scour channel go downstream?
- How far does this scour channel go upstream?
- What material is at the end of this scour channel?
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