Australia - Seismic Activity And Faulting

As it drifts north, the Australian plate is colliding with the Pacific and Eurasian plates, forming a subduction zone (an area where one continental plate descends beneath another). This zone, the convergence of the Australian continental plate with Papua New Guinea and the southern Indonesian islands, is studded with volcanos and prone to earthquakes. Yet Australia is unique in that it is not riven by subduction zones like other continents. There are no upwelling sections of the earth's mantle below Australia (the layer below the crust), nor are there intracontinental rift zones like the East African Rift System which threatens to eventually split Africa apart.