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, multiple processes are taking place that ultimately lead to the tree falling down to the river. Let's break it down using the concepts of weathering.
1. Mechanical Weathering: Mechanical weathering refers to the physical breakdown of rocks into smaller pieces without any change in their chemical composition. In this scenario, the tree's roots are gradually exerting pressure on the rock, causing it to crack. This is an example of mechanical weathering as the physical force of the tree's growth is resulting in the rock's breakdown.
2. Chemical Weathering: Chemical weathering involves the alteration of rock material through chemical reactions. Although not explicitly mentioned in the example, chemical weathering may also be occurring over time due to the water runoff from the house. Rainwater can carry dissolved acids and other substances that react with the rock, further weakening it. This chemical process can contribute to the rock's eventual cracking and deterioration.
3. Biological Weathering: Biological weathering involves the breakdown of rocks by living organisms. In this case, the tree's roots play a role in biological weathering. As the roots grow and expand, they exert pressure on the rock, aiming to find more space and nutrients. This prolonged action weakens the rock, making it more susceptible to mechanical and chemical weathering.
Overall, the combination of mechanical, chemical, and biological weathering processes is causing the rock to crack and eventually collapse. The increased water runoff from the construction of the house above exacerbates the situation, providing additional moisture that encourages the tree's roots to grow faster and bigger. Ultimately, the weakened rock structure can no longer support the weight of the tree, leading to its collapse into the river.