If a tree has grown out of the side of a rock cliff and a house was recently built on the land above causing the tree a lot more rain water to run off where the tree lives, it's roots have started to be exposed and are now growing faster and bigger with the increase of water. The rock eventually cracks and the tree falls down to the river.
Explain what is happening in this example using the words weathering or erosion and chemical, biological and or mechanical weathering.
In this example, we can observe a combination of weathering processes, including chemical and mechanical weathering, leading to erosion and eventually the collapse of the tree and the rock. Let's break it down step by step:
1. Chemical Weathering: Over time, as rainwater comes into contact with the rock cliff, certain chemicals from the water can react with the minerals present in the rock. This chemical reaction weakens and breaks down the rock's structure. However, it's important to note that this process alone is generally slow and may not lead to an immediate breakdown of the rock.
2. Mechanical Weathering: The tree, growing out of the side of the rock cliff, contributes to mechanical weathering. As the tree's roots grow and penetrate into the cracks and crevices of the rock, they exert pressure, causing the rock to weaken and eventually crack even further. This process is known as root wedging.
3. Additional Rainwater from House: When a house is built on the land above the rock cliff, it changes the natural drainage patterns. The new construction may cause an increase in the amount of rainwater running off onto the rock cliff, providing more water for the tree in that area.
4. Biological Weathering: With the amplified rainfall, the tree receives a considerable amount of water, which allows its roots to grow faster and larger. As the roots expand, they exert more pressure on the rock, further contributing to its weakening and potential fracture. This is an example of biological weathering through the actions of the tree.
5. Erosion: As the rock weakens due to both the chemical and mechanical weathering processes, it becomes more susceptible to erosion. Eventually, the rock will not be able to withstand the forces acting upon it, leading to the cracking and eventual collapse of the rock face.
Overall, the combination of chemical weathering, mechanical weathering (root wedging), increased water supply due to the new house, biological weathering (root growth), and erosion all work together to cause the tree to fall and the rock to crack, ultimately ending up in the river.