How is the yearly rate of tectonic plate movement typically measured?

The yearly rate of tectonic plate movement is typically measured in centimeters. This measurement is most appropriate because the movements of tectonic plates are relatively slow and gradual over geological time. Most tectonic plates move at rates ranging from about 1 to 10 centimeters per year, which makes centimeters the most practical and convenient unit for representing these small and precise movements.

Using meters or kilometers would imply much larger movements than occur annually, potentially leading to significant inaccuracies in understanding tectonic dynamics. Although millimeters might also seem viable, they would involve excessive precision for the overall rates of movement observed. Thus, centimeters strike a balance between adequate precision and relevance in the context of geological measurements, making this unit the standard in tectonics research.