Detective Matt Jones, the officer in charge of the investigation, said the youth had been referred to Youth Aid.
Police have refused to answer questions about why it took more than an hour to begin the evacuation of the terminal.
The airport's chief executive, Colin Keel, said in the statement he was pleased the source of the threat had been identified.
``The safety and security of our visitors and airport and that of our local communities always come first,'' Mr Keel said.
The airport's communications manager, Jen Andrews, said it would not be making any further comment as justice proceedings were under way.
Qantas Airways senior manager of corporate communications Stephen Moynihan said the company thanked police for pursuing the matter.