Causes of Earthquakes

Earthquakes usually happen at the aforementioned borders of those continental shelf. The most severe earthquakes usually occur at the border of compressional and translational plates. Deep-focus earthquakes are most likely due to the material sandwiched in the lithospheric layer undergoing phase transitions at depths of more than 600 km.

Several other earthquakes can also occur due to the movement of magma inside the volcano. Such an earthquake can be a symptom of a volcanic eruption. Some earthquakes (rarely but) also occur because of the massive buildup of water masses behind the dam, such as the Caribbean Dam in Zambia, Africa. Some (rarely) can also occur due to injection or extraction of liquids from / into the earth (for example in some geothermal power plants and in Rocky Mountain Arsenal. Finally, earthquakes can also occur from explosive explosives. This can make Scientists monitor confidential tests of nuclear weapons by the government, and human-caused earthquakes like this are also called induced seismicity.