Step-Over and Bend Structures along the 1999 Duzce Earthquake Surface Rupture, North Anatolian Fault, Turkey

摘要

The 12 November 1999 Duzce earthquake (M_w 7.1), which occurred on the Duzce fault of the North Anatolian Fault Zone, formed a 40-km-long surface rupture, which extended between Golyaka in the west and Kaynasli in the east. The earthquake nucleated close to the Beykoy step-over, a 0.8-km-wide and 1.8-km-long pressure ridge, with bilateral rupture propagation both to the west and the east. The Beykoy, Kaynasli, and Cevizlik step-overs, through which the 1999 Duzce rupture propagated, are less than 2.5 km wide. The Eften and Bakacak step-overs, where the rupture was arrested, are more than 4 km wide. These exceptional dimensions of step-overs associated with the 1999 Duzce rupture were investigated for their influence on rupture propagation.