Existing comment:
A Canyon Profile:
Do you notice a difference in the canyon walls here? One side is sheer and rocky, while the other side slopes gently and has more plants. This pattern is found throughout canyon country.
Cliffs on the north side are sheltered from direct sunlight. This slows the cycle of expansion and contraction that weakens rock and results in rock falls. With less sunlight, water evaporates slower, helping to build soil and allowing plants to take root. Plants slow erosion by anchoring the soil and sheltering underlying rock from the elements.
North-facing walls usually slope gently and have more trees, while south-facing canyon walls are rugged and barren. |