A contractor friend says we don't need permit or engineering for this kind of work. A n earthquake is a natural shaking of the ground, caused by sudden slippage of rock on a fault-line. Seismic waves spread outward from the fault rupture much like ripples do in a quiet pond when a stone is thrown into it. These slabs of rock are called tectonic plates. They are constantly crunching, grinding, moving into, under, over, and past each other.
Tremendous pressures build up as the plate edges lock against each other.
Every now and then accumulated pressures will force the edge of one massive plate past the other releasing the spent up energies of uncounted centuries. S ometimes the plates only jump a tiny bit causing windows to rattle. Other times the displacement is so violent that it sends seismic waves booming out in all directions with force of many atomic bombs. The result is called an earthquake. We may never see any degree of pin point accuracy.