Continental plates drift as fast as fingernails grow

Continents shift at approximately the same speed that our fingernails grow (which is apparently much faster than our toenails grow!). They move just millimeters at a time, moving about 20 millimeters in an entire year. To put that in perspective, it took the supercontinent Pangea millions and millions of years to split into the continents that we see today, and it will likely take millions of years more for them to shift far enough to come crashing into one another again.