Important things to know to avoid log deletion:
- if your answers will be sent at a later time, state when I will receive them in your found log.
- required photo must be AT GROUND ZERO and personalized in some way so that I know you were truly there.
- finds after October 1, 2022 must include your photo taken at the lower level at the posted coordinates.
If I delete your found log due to lack of following instructions, you can re-log your find when you are able to comply.
Cache description
Water has a great effect on the shape and form our land takes. In the end, it is the superior element. On a planet whose surface is eighty percent water, water wins.
We The People must be like water on a rock. A splash won’t damage it. But a river will ALWAYS win in the end.
Water erodes rock mechanically and chemically. Scouring, abrading, and gullying occur when fast-moving water scrapes its silt, gravel, and rock debris against firmer bedrock. Slow-moving or standing water enters minute rock pores and dissolves cements holding the rock together, leaving loose grains to wash away.
Erosion is the process by which soil and rock particles are detached and removed from one another. This is done through the wind or much more likely through water. The water will force the elements out a little at a time and float them down to some other part of the world to be deposited. The rock elements still exist but the land formation now looks worn and altered. It is important to note that weathering is not the same as erosion. Many people mistake the two for each other. Weathering is the actual destruction of the rock particles and erosion is merely their transport.
EROSION:
Running water erodes land formations in three main ways:
The first is by dissolution of the rock types such as limestone or rock with calcite deposits.
The second way water erodes land formations is by scouring or lifting loose particles from the formation and depositing them elsewhere. The more powerful the force of the water’s action, the more scouring occurs.
The third way in which water erodes land formations is by abrasion. This is where the rock particles from other structures in the water become a weapon. The water is now like sandpaper rubbing against the formation. Once again, the more powerful the water’s action, the more powerful the abrasion will be.
WEATHERING:
When water seeps into cracks in rocks, it enlarges them by washing pieces away and/or chemically dissolving the rock. A determining factor on how quickly rock will erode by water is the rock type. Harder rock, such as quartzite, takes longer to dissolve than softer rock, like mudstone. Quartz pieces are more likely to be transported than dissolved. Mudstone pieces can be transported but usually dissolve much faster during transportation. Water erodes rock easily when impacting the carried rock with stream bed rock. The broken rock pieces continue to flow and impact down stream. This is why river rock is rounded and smooth.
EROSION AND WEATHERING IN RIVERS:
One of the most obvious results of erosion and weathering is the formation of river valleys. At the top of these the water tends to be fast and bubbly, producing white water rivers with the power to carve gorges from the power of the water. They do this by picking up material from the riverbed and abrading the surface of the rock, by breaking it down using the slight acidity in the water, and by forcing itself into cracks and opening them wider. As time goes by, the gorge deepens, and as the water passes over divides in rock types, erosion may occur faster or slower. This will create a shelf in the riverbed, producing a waterfall. As the water pours over the edge, it swirls back on itself and this undercuts the edge of the shelf, which in turn may cause the top of the shelf to collapse. Over the years, the waterfall will retreat up the gorge.
As the river widens and deepens, it will move more slowly, and so rather than carving out gorges it will form gently sloping valleys, and then move onto the plains as it heads for the sea.
Bends in the rivers are known as meanders, and as the water winds its way round them it moves faster on the outside of the corners, undercutting the bank, forming river cliffs. On the inside of the corner the water is often moving slowly enough to deposit the material it is carrying, and a river beach is produced.
As time goes past, deposition and erosion will cause the river to meander so much that it loops round and joins itself again. This creates a new channel that is straighter, which the water will choose over the bend. Deposition along the banks will cut off the old meander, which will eventually form an oxbow lake.
When the water meets the sea it combines with the seawater, and deposits most of the remaining material it is carrying, thus partly blocking the river, and forcing it to spread out into an estuary.
FINDING THIS CACHE:
To claim a find on this cache please do the following:
1. Walk to the given coordinates where you will take your photo, and as you go observe the effects of erosion and weathering - the results of water.
2. Go to the posted "Pot Holes" waypoint coordinates on the bridge. (N 47° 1.092' W 122° 54.257') Look down (upstream) to the rocks next to the fish ladder to determine the answer for 3c. You will see some pot holes in the rocks. You may have noticed more of these along your walk.
3. Send the following to me:
- a) the condition of the falls at the time of your visit - fast, slow, wide, etc.
- b) two effects of water on rock (in addition to the pot holes) - types of erosion and weathering you observe on your walk.
- c) why and how you think the pot holes were formed - be detailed - do a bit of research if necessary.
4. Log your find with your photo attached to your log.
5. Photo requirement - post a photo with your found log of yourself on the bottom level (posted coordinates) of the walk showing the falls in the background. Photos taken from other locations will not be accepted. Camera shy? Write your name on a piece of paper, or use something else to identify yourself, then photograph it with the base of the falls in the background.
If the entire area is covered with water (rare other than a few times a year) tell me and I will send you a photograph to use to answer that question.
After October 1, 2022, all posted found logs must have photos taken at ground zero on the lowest level. The only exception is during high water season, when you may be stopped a few feet short of your objective. If this is the case, take your photo with the barrier showing.