What is the principle of uniformitarianism?

The principle of uniformitarianism, a foundational concept in geology, asserts that the processes that have shaped the Earth over geologic time are the same processes that can be observed operating today. This means that by studying current geological and environmental processes—such as erosion, sedimentation, and volcanic activity—scientists can make inferences about how similar processes occurred in the past, even millions of years ago.

This principle allows geologists to reconstruct geological history and understand the Earth’s past environments and the changes it has undergone. It underscores the idea that the natural laws and processes, such as gravity or the cycles of rock formation and erosion, have remained consistent over time. This consistency is essential for making geological predictions and understanding patterns in Earth’s history.