Differences in seasonal variations in the patterns of diurnal earthquake periodicity in the southern and northern hemispheres

Seasonal variations in the form of diurnal periodicity are compared in three regions of the world, two of which (Alaska and Japan) are located in the Northern Hemisphere and one (New Zealand) is in the Southern Hemisphere. It is found that, in the Northern Hemisphere, the duration of the night interval of an increased number of earthquakes in December is greater than in June, while in the Southern Hemisphere it is smaller. The intra-annual character of variations in the form of diurnal earthquake periodicity agrees with the seasonal variations in the length of the day.