The earth’s tectonic plates are always moving. we can measure their movements using gps, just like we can track a car or a teenager with a cell phone. ; -) given that the plates are always moving, why do we have only occasional earthquakes—rather than constant

The tectonic plates are continuously moving and earthquakes are happening all the time.

Explanation:

An earthquake is the seismic waves travelling through the lithosphere. They occur along tectonic plate boundaries and faults. In areas that are far from these plate boundaries and faults, earthquakes are less likely to be felt. The size of the earthquake is mostly unnoticeable. Bigger earthquakes happen with a build of tension that is suddenly released. It does not happen as often because it takes time to build up the pressure.