What will happen to travelers with an Australian visa who don't depart from the Australian Migration Zone? 
Australian citizens and residents from other parts of the nation now have automatic right of residence on the island after meeting these criteria (Immigration (Amendment No. 2) Act 2012). Australian citizens must carry either a passport or a Document of Identity to travel to Norfolk Island. Citizens of all other nations must carry a passport to travel to Norfolk Island even if arriving from other parts of Australia. Holders of Australian visas who travel to Norfolk Island have departed the Australian Migration Zone. Unless they hold a multiple-entry visa, the visa will have ceased; in which case they will require another visa to re-enter mainland Australia.