I would say that two of the plates were sliding past each other, got stuck, and slipped past each other so fast that it caused pressure rising to the surface, and caused an earthquake.
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismic activity of an area refers to the frequency, type and size of earthquakes...
technically yes Poseidon is storm bringer but he only bring earthquakes to places that have a bad background such as California the flame of the west has move from Greece to right here in America,...