Disaster Management in Perth WA and the Tsunami Threat

It is among the most iconic footage of a disaster that has ever been caught on camera. On Boxing Day of 2004, a megathrust earthquake to the west of Sumatra created a colossal tsunami, spreading out in all directions, and causing destruction and chaos to shorelines as far away as east Africa.

The worst damage occurred closest to the epicentre in Aceh province. The city of Banda Aceh was severely impacted, constituting the bulk of the casualties, but it was the west-facing communities in Sumatra where the damage was most extreme. Here, eyewitnesses reported a wave that was as high as 35 metres – the tallest tsunami of modern times.

These waves are created when massive quantities of seawater are displaced through undersea seismic events. Given the colossal stretch of ocean that adjoins Perth and all of WA, disaster management has been obliged to look in to potential methods of remediating the risks of such an event here. It isn’t so much a question of ‘if’ – Western Australia experiences a tsunami event roughly every ten years.

Many of these are relatively minimal, recorded only by tide gauges. But some have been considerably more noticeable. Faults off of Java, in Indonesia, have caused waves to sweep inland for hundreds of metres, typically off the sparsely-inhabited northern coast of the state. And larger events, including the 2004 tsunami, have caused erosion and damage to areas of the coast as far south as Albany.

The low elevation of the land here makes the importance of a disaster management plan especially important for Perth and WA. A larger tsunami could sweep inland several kilometres inland, destroying homes and property, and making the land saline and sterile. As part of the Bureau of Meteorology, the Joint Australian Tsunami Warning Centre (JATWC) is responsible for providing prior warning of such events, and keeps an eye on seismographs from around the world to do so.