The gulf was created by the expansion of a tectonic rift due to the westward movement of the Anatolian Plate .
The gulf was expands by 10 mm ( 0.39 in ) per year .
The gulf was created by the expansion of a tectonic rift due to the westward movement of the Anatolian Plate , and expands by 10 mm ( 0.39 in ) per year .