The NAFZ is the most prominent active fault in Turkey and has been the source of numerous large earthquakes throughout the history. The NAFZ zone splays into three strands to the west of about 30.5E (Barka and Kadinsky-Cade, 1988). The northern strand passes through Izmit Bay and traverses Marmara Sea and reaches to the Saros Gulf to the southeast. Several researchers considered that the Marmara Sea region is a graben structure (i. e. Crampin and Evans, 1986). To explain the structure of the northern strand of the NAFZ in the Marmara Sea, Barka and Kadinsky-Cade (1988) and Wong et al. (1995) have developed similar models, that considers right stepping en echelon strike-slip segments giving rise to small open basins and blocks as pull-apart structures.

Additional Information on NAFZ:
Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering

NAFZ and rupture sequence(226Kb!)