The Australian coastline has experienced tsunami through recorded history but most have been marine based threats and have presented little threat of land inundation to our coastal communities. Despite this, unusual rips or currents caused by even relatively small tsunami can be dangerous to marine users and boats. The offshore tsunami hazard to Australia varies from 'relatively low' for most of our coastline to 'moderate' on the north-west coast of Western Australia (WA). This is due to its proximity to Indonesia and other countries in that region prone to large undersea earthquakes and volcanic activity.
In May 1960 a magnitude 9.5 earthquake along the tectonic plate boundaries off the coastline of Chile, resulted in the largest recorded tsunami along the east coast of Australia. The event generated tsunami waves just under one metre in height in Sydney Harbour. Slight to moderate damage (mainly to boats) was recorded in harbours at Lord Howe Island, Evans Head, Newcastle, Sydney and Eden.
The impact on Australia during the December 2004 Indian Ocean Tsunami was relatively minor. Although the more destructive waves did not travel towards Australia during this event, a half metre tsunami wave passed the Cocos Islands and dangerous rips and currents were experienced on the western and southern coasts of Australia. At least 30 people were rescued after being swept out to sea, some relatively minor land inundation occurred and boats were damaged in marinas. Fortunately no lives were lost.
On 17 July 2006 a magnitude 7.7 undersea earthquake south of Java generated a tsunami that affected parts of the WA coast, particularly Steep Point. Waves of up to two metres were recorded with evidence of inundation up to 200 metres inland. This tsunami caused widespread erosion, extensive vegetation damage and destroyed several campsites.
Campers at Steep Point were lucky to escape when the July 2006 tsunami inundated their beach campsite, picked up their 4WD vehicle and moved it ten metres up the beach. Fish, starfish, corals and sea urchins were also deposited on roads and dunes well above the regular high-tide mark.
On 2 April 2007 an 8.1 magnitude undersea earthquake off the coast of Gizo in the Solomon Islands caused tsunami waves between two metres and ten metres high. The tsunami caused widespread destruction in the Solomon Islands with a death toll of 34. As a result of this event, a senior Surf Lifesaver of 30 years experience at Coffs Harbour on the New South Wales north coast claimed there were dangerous rips and currents in the town's harbour, something he had never witnessed before.