In late July, it was announced that the US would be allowed to use Incirlik airbase in Turkey to conduct airstrikes against ISIS. This move came immediately after ISIS claimed responsibility for a bombing in Suruç, Turkey that killed 33 people. It has been widely reported that the US/Turkey deal also included a provision for some sort of safe zone, or ISIS-free, zone along the Turkish-Syrian border.
US officials have denied that this zone would be a true safe zone or no-fly zone, but rather that the US and Turkey would collaborate to clear a zone from ISIS control and look to man it with moderate opposition fighters. According to Foreign Policy, Turkish Foreign Minister Mevlut Cavusoglu has said that the zone will not be an official no-fly zone but will have US air support. President Erdoğan has stated that the zone could allow for 1.8 million Syrian refugees to be repatriated.
News sources are generally in agreement that the zone would extend west along the Syrian border from Jarablus on the Euphrates. Some reports state that the zone will extend as far as Marea, while others state that it will extend as far as A’zaz. The depth of the zone is less certain, but reports indicate that it will be 40-50 km deep. Assuming a depth of approximately 45 km, the zone would look like this if it extends to Marea: