EARTHQUAKE TRIGGERING IN GREECE AND THE CASE OF THE 7 SEPTEMBER 1999 ATHENS EARTHQUAKE

摘要

The case of the Athens earthquake (M_w=5.9) of 7th September 1999 is examined as a triggered event by the Izmit large (M_w=7.4) earthquake of 17 August 1999. It is shown that the probability for the Athens earthquake to occur randomly 21-days after the Izmit event is less than 1.5x10~(-3). In addition, it was found that the microseismicity of the Athens increased drastically immediately after the Izmit shock culminating with the main shock. It is suggested that ordinary (or triggering) earthquakes trigger distant microseismicity and this triggers secondary (or triggered) earthquake.