My Earthcaches Around the World
How rivers are borned
When I was traveling around Java, I found a lot of beautiful and interesting places without any cache. And so I made a three of them around Java and probably many more in every country I visit in the future. Like now in Malaysia. Now to the location.
Basic information
Tropical rivers are among the most dynamic systems on Earth. Due to extreme rainfall during the monsoon season (November–March), riverbeds change literally before your eyes. The water flow can increase several-fold within hours, giving the river immense power for erosion and sediment transport.
As you look around, you see the result of thousands of years of water work. In addition to the prominent sand islands (depositional forms), the river constantly creates erosional features like steep, eroded banks on the outer curve of a bend where the water strikes with the greatest force or exposed Bedrock Sills, areas where the water has washed away all sediment, revealing the hard bedrock made of sandstone or shale.
The large island in front of you is the result of a process called sedimentation. A tropical river carries materials of various sizes. This island is primarily composed of two components: sand and gravel (pebbles), .
Why are they not mixed together, but often separated into zones? The key is the kinetic energy of the water:
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Gravel and Stones: These are heavy. It takes a very strong current to move them. As soon as the river calms slightly after a flood, these heavy parts settle first (often forming the "core" or the upstream head of the island).
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Sand: It is light and remains in motion even in a moderate current. It only settles in calm zones, in the lee of an island, or in places where the flow widens and slows down. This process is known as hydraulic sorting.
Right at your feet, on the bank or in the riverbed, a constant process of abrasion (grinding) is taking place. Water alone does not grind stone; it uses "tools" – sand and smaller pebbles that it carries. When you look at the large boulders in the riverbed, you will notice they are:
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Smooth: Water mixed with sand acts like sandpaper, smoothing the rough surface of the rock.
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Rounded: The current strikes against sharp edges, which break off and wear down over time until the stone acquires a typically rounded shape.
In Kuala Tahan, this process is extremely rapid due to the massive amount of material transported during floods.
Questions
Posted coordinates - the river bank
1, Which formation (non-human) of fluvial erosion, other than the sand island in front of you, you might see in the surroundings? Name at least one.
2, Look at the big island. Which compounds is it made of? There are two of them. Why are they separated from each other?
3, Below you is one other source of water erosion - abrasion. Describe the properties of the large stones under your feet
4, Take a photo at one of the stages of you or your personal item (GC, pathtag, xWG or any other you have) and post it with your log. Logs without a photo are not valid and will be removed.
I hope you'll like this cache and the place where it's located.
Happy geocaching!