Answer:
Transform Boundaries
Explanation:
Transform Boundaries are where two plates move basically horizontal compared to one another. However, as they move friction increases and they sort of get locked up because of imperfections in the surfaces or subsurface.
When this pressure gives way, the plates 'pop' in this case causing an earthquake. These are the type of boundary movements which are most responsible for causing earthquakes, but other types of plate movements can also cause earthquakes; just not nearly as often as a Transform Boundaries will.
