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Getting prepared for the next big wave
Just three months before the tsunami smashed its way across southern Asia, Geoscience Australia published a four page report saying that Western Australia was vulnerable to seismic sea-waves and that an early warning system for the Indian Ocean should be installed.
As it turned out, the tsunami that struck on Boxing Day killing more than 300,000 people caused little more than a ripple along the Western Australian coast. But coinciding so closely with the Geoscience warning, it represented an uncomfortable reminder of the State's exposure.
Six hours after the first undersea quake a high surge of water was recorded 4000km from the epicentre at Exmouth. Soon after a 1.5 metre wave was sweeping the shore at Geraldton and later when it reached Busselton, it swamped a local beach and two people needed rescue.
This time Western Australia suffered no serious damage. But with much of the State's wealth invested in coastal communities and some of its largest industrial development either on or near the sea, the Boxing Day tsunami has been a wake-up call.
According to Geoscience Australia's report, the greatest tsunami threat posed to Australia is that caused by tectonic plate movement off the northwest coast of Indonesia - the same area that sent the latest tsunami rushing across southern Asia.
Woodside Energy has taken heed of the warning. As one of the principal shareholders in the multi-billion dollar North West Shelf petroleum project, it announced in January it will be a major contributor to a research study of seismic activity and earthquake risks in the vicinity of the shelf.
The research is to be conducted jointly by the University of Western Australia, and the ANU.
THE Western Australian Premier, Dr Geoff Gallop has voiced his support for the creation of an international early warning system for the Indian Ocean and other countries in the region are now eager to develop such a facility. Japan, which is particularly prone to tsunami events, has also offered to take a lead roll.
There is already a tsunami-warning network serving Australia's eastern seaboard. It came into being after the 1960 Chilean earthquake sent a tsunami across the Pacific and with it a one-metre wave into Sydney.
While the latest tsunami caused waves only 1.5 metres high in Western Australia, the State has experienced much worse. According to Geosciences Australia an earthquake in Java sent a 4 metre high tsunami onto the northwest coast in 1994 and in 1977, an earth-quake in Sumbawa generated waves 6 metres high on the north-western coast.
At the time they caused little damage - primarily because the population was so sparse in the areas hit. But the increasing numbers of people now living in and visiting the area has also increased the State's vulnerability, according to Geosciences.
In its report, Geosciences Australia calculates that the North West Shelf would probably have been hit by the tsunami generated by the world's largest volcanic eruption in recent history - the eruption of Krakatau in the Sundra Strait in 1883. Geoscience says there are no reports from the period to actually describe what might have happened in WA's northwest.
But German geoarcheologist, Eberhard Zangger in his recent book states that the sound of the 2000 metre high Krakatau exploding was audible in both Singapore and northern Australia.
"Although the island of Krakatau itself was uninhabited, the event claimed more than 36,000 lives," writes Dr Zangger.
"During the eruption, immense waves, known as tsunamis, were repeatedly created, the largest of which reached a height of thirty to forty metres. These surges devastated 165 coastal settlements in Java and Sumatra. A gunboat belonging to the Dutch navy was carried almost three kilometres inland."
