TWO US Marine Corps jets have been forced to drop four unarmed bombs on the Great Barrier Reef. The two AV-8B Harrier jets each dropped two 226kg bombs on the world heritage-listed reef in an emergency jettison during a training mission on Tuesday. The incident came ahead of Exercise Talisman Saber, a biennial training operation between Australian and US forces based at Shoalwater Bay on the central Queensland coast. The dropped bombs had not detonated and a US official has reportedly said the chance of any of them exploding is "extremely remote". A Great Barrier Reef Marine Park Authority spokeswoman...