It is strange, but the causes of earthquakes are still not fully understood. Earthquakes are generated in different parts of the crust and the sub crustal layer, i.e., apparently in a solid medium. Most modern scholars believe that the immediate cause of earthquakes is the displacement at depth in the substance of the Earth, associated with or momentary shift, sliding, or twisting of the substance. This is proved by the fact that the earthquake hypocenters are located along the planes of the pre-existing discontinuities of the crust. Many of the earthquakes on the Pacific coast of North America were linked to known tectonic San Andreas fault in California. Earthquake hypocenters from the Crimean peninsula located within a narrow band inclined from the bottom of the Black Sea, with the Crimean Peninsula.

The same pattern of distribution centers is observed along the shores of the Sea of Okhotsk. Probably, in both cases there are major faults, whose planes are tilted toward the land. For these faults the region of the Crimean Peninsula and the Far East coast are moving towards the sea. These movements cause stress, which bind the repeated ruptures along pre-existing disturbances in the Earth's crust, and these gaps in turn cause an earthquake.

The hypothesis of a discontinuous origin of earthquakes proved by the fact that a number of earthquake-waves formed as the time shifts are more intense than the longitudinal wave. In the case of simple compression and extension agents without breaking the longitudinal waves should have been stronger.

Careful analysis of seismograms helps identify the causes of earthquakes. The developed apparatus allows studying separately the longitudinal and transverse waves, and probably in the near future will finally find out the cause of earthquakes.

Earthquake surface type is more diverse in origin. They can be caused on the one hand, the tectonic causes, and on the other - volcanism, collapse into the voids on the surface and near it.

Some scientists link the shallow earthquake with atmospheric phenomena. This assumption is based on the fact that most earthquakes in the northern hemisphere have in the winter months, some earthquakes have followed severe thunderstorms or hurricanes. It was found that the case not in the storms or thunderstorms, and change the gradient of atmospheric pressure.

Change of atmospheric pressure, of course, did not create but only caused the earthquake, and only in the case when the stresses in the crust have been close to the imbalance.