Site map . Earthquakes with magnitudes between 7.0 and 7.9 are classified as major earthquakes. For there year, so far, there have been 13 major earthquakes around the world. Since 1900, the average number of major earthquakes annually has been 18, according to the U.S. Geological Survey. The annual number of major earthquakes, tallied worldwide, does not vary widely, because most major earthquakes are the result of tectonic plate interactions, and these interactions occur at a steady rate, geologists say.
Plates slide past, collide with, and dive beneath one another.
Stresses accumulate along the boundary until the impediment can be overcome, and the locked section of the plate moves to catch up with the rest of the plate. The result of this snapping action is an earthquake. The deadly temblor in Turkey on Aug. 17 was along the North Anatolian fault, where the Turkish microplate is sliding past the Eurasian plate. There were more than 15,000 fatalities, primarily caused by the collapse of nearly 76,000 buildings. The earthquake caused the collapse of over 38,000 structures and killed more than 2,300 people.