Japanese TV warning of tsunamis, Sept. 2004.Image credit: Wikipedia.
by Ian MacKinnon
On Tuesday, Indonesia launched a sophisticated new tsunami warning system designed to give coastal residents enough time to flee or seek shelter from an impending tidal wave.
The national system aims to protect the inhabitants of the archipelago's vast coast and prevent a deadly repeat of the 2004 Indian Ocean tsunami that killed 168,000 people in Indonesia alone.
But even as President Susilo Bambang Yudhoyono inaugurated the system in Jakarta, officials conceded it would be several years yet before it is fully complete and the whole coastline protected.
In particular, deep-sea warning buoys have yet to be installed around Bali, Flores and northern Sumatra — which includes Aceh where most lost their lives in the tsunami — with the result that there could be delays in predicting a tsunami and issuing warnings.
However, much of the complex system of sensors, satellite communications and computer modelling is already in place ahead of the 2010 completion target and was able to predict the tidal wave that struck the Sumatran coast last September.
The Boxing Day 2004 tsunami was the result of an earthquake below the seabed measuring 9.3 on the Richter scale. The surge it triggered struck the Banda Aceh coast within 15 minutes, but in the hours that followed the devastating impact left 240,000 dead around the region.
Yet Indonesia, with its 17,000 islands, remains especially vulnerable because it sits on the meeting point of three of the earth's tectonic plates, leaving 60% of the coastline at risk from tsunamis.
The new high-speed warning system connects a series of seabed sensors that detect the earthquakes that may set of a tsunami, information that is relayed to buoys on the surface.
Deep-sea pressure gauges monitor any sudden variations indicating that a tsunami is in motion, data that is enhanced by the notion of the surface buoys that carry global positioning systems.
All the information is relayed by satellite to the tsunami early warning centre in Jakarta, which is connected to 11 regional hubs across Indonesia.
The real advance, though, is that the snippets of information are fed to a computer which evaluates it in conjunction with pre-programmed scenarios that will, within minutes, give a simulation of arrival times and wave heights, enabling fast and accurate warnings to be issued in the event of an emergency.
But even a perfectly working system, which was jointly developed with Germany, can only reduce and not completely eradicate the dangers posed by such a natural catastrophe.
"We are starting the world's most advanced tsunami early warning system able to issue the quickest possible warnings with a high degree of reliability," said Thomas Rachel, Germany's parliamentary state secretary, in Jakarta.
This article originally appeared on The Guardian. Ian MacKinnon is their south-east Asia correspondent.