Answer:
Tectonic plates
Explanation:
In general, earthquakes are due to the immense vibrations from the shifting of tectonic plates. In the specific case of the San Andreas Fault, there is one issue. It is directly on top of a boundary between two tectonic plates. So, when either one of the plates shifts, extreme earthquakes occur due to the location being on top of the source.
Dark matter makes up about 27% of the universe.