Regions of the Earth with the best-pronounced annual period of seismic activity

A number of relatively small regions of the Earth have been found where the annual periodicity of seismic activity is most prominent, i.e., the Balkans and Turkey, an isthmus between North and South Americas, Alaska and the Aleutians, and some others. In both hemispheres, these regions are associated with subduction zones or intensely faulted segments of the continental crust.