The North Anatolian Fault (NAF; Turkish: Kuzey Anadolu Fay Hattı) is an active right-lateral strike-slip fault in northern Anatolia, and is the transform boundary between the Eurasian plate and the Anatolian sub-plate.

The fault extends westward from a junction with the East Anatolian Fault at the Karliova triple junction in eastern Turkey, across northern Turkey and into the Aegean Sea for a length of 1200[1]−1500 kilometers.

The Sea of Marmara near Istanbul is an extensional basin similar to the Salton Trough in California, where a releasing bend in the strike slip system creates a pull-apart basin.

[5] By analyzing the stresses along the fault caused by each large earthquake, they were able to predict[quantify] the shock that hit the town of İzmit with devastating effect in August 1999.

It is thought that the chain is not complete, and that an earthquake will soon strike further west along the fault – perhaps near the heavily populated city of Istanbul.