The nucleation of the Izmit and Düzce earthquakes: some mechanical logic on where and how ruptures began

SUMMARY In spite of growing evidence that many earthquakes are preceded by increased seismic activity, the nature this activity is still poorly understood. Is it result a mostly random process related to natural tendency events cluster in time and space, which case there little hope ever predict earthquakes? Or sign physical will lead impending rupture has begun, we should attempt identify process. With aim take further look at nucleation two best recorded documented strike-slip date, 1999 Izmit Düzce ruptured North Anatolian Fault over ?200 km. We show existence remarkable mechanical logic linking together characteristics, stress loading, fault geometry speed. both observations point slow aseismic slip occurring near ductile-to-brittle transition zone as motor their nucleation.