What evidence suggests that plates are in motion relative to each other?

The evidence indicating that tectonic plates are in motion relative to each other is best reflected in the patterns of earthquakes correlating with fault lines. When tectonic plates interact along these fault lines, they can generate stress that leads to earthquakes. These seismic events are often concentrated along specific zones where the plates are either colliding, sliding past one another, or moving apart, highlighting the dynamic nature of the Earth's lithosphere.

The distribution and frequency of earthquakes provide a clear and direct correlation to the movement and interactions of these plates, allowing scientists to track their motion and the associated geological processes. This relationship between seismic activity and plate boundaries is a fundamental aspect of plate tectonic theory, offering insights into the behavior and fate of the Earth's crust.

Other factors, such as the permanent positions of tectonic plates, do not suggest movement since they imply stability rather than change. Similarly, while the consistent elevation of mountains can be associated with tectonic activity, it does not directly indicate the relative motion of plates at a given moment. Lastly, linear features in sedimentation can result from various processes, including sediment transport and deposition, and cannot definitively point to the motion of the plates themselves.