Aftershocks of February 19, 1968 earthquake in Northern Aegean Sea and related problems

Summary The aftershock activity associated with the North Aegean Sea earthquake of February 19, 1968 (M _s =7.1) has been studied with emphasis on the time and magnitude distributions. Regarding the focal mechanism it was noted that the sense of first motion remains rather unchanged throughout the sequence.The secondary series are not distinct in space or time or mechanism from the primary sequence. Although the main shock was followed by almost 3000 aftershocks (M _L 2.1) which form the basis for this study, principal strain has been released by the main shock which is responsible for the 82 per cent of total strain release in the sequence.