Japanese scientists are among the leaders in tsunami-warning technology. But even as they develop new computer and satellite systems to spot potentially deadly waves, many experts worry that developing countries lack the infrastructure to ensure coastal residents are warned in time to reach higher ground.
The December 26th earthquake and tsunami in the Indian Ocean stunned seismology experts, who had no indication such a calamity could occur there. Makoto Murakami of the Japanese Geographical Survey Institute in Tsukuba was among those caught by surprise.
"I personally didn't know the possibility of the occurrence of such a huge earthquake in that region and, of course, naturally I didn't expect such a huge tsunami can attack that region."
Mr. Murakami heads a project to develop a satellite-based tsunami monitoring system. The cutting-edge system relies on a phenomenon called cluster deformation. As an earthquake or tsunami occurs, it moves the air, sending vibrations and disrupting electrons in a region of the sky called the ionosphere.
This disturbs the microwave frequency signals sent from global positioning satellites to ground sensors. Mr. Murakami says if banks of computers can analyze these disruptions as they happen, the direction, speed and size of a tsunami can be predicted.
"If we can do that, we can detect cluster deformation associated to the large earthquake, huge earthquake, offshore, a long time before the actual arrival of tsunami wave because the propagation velocity of the seismological wave is much faster than tsunami."
Japan already has a nationwide network of 12,00 GPS sensors. The data they recorded during December's earthquake is being analyzed by the Paris Geophysical Institute, which is working with Mr. Murakami's team.
The French scientists plan to determine how accurate such a real-time warning would have been. Japan, which is vulnerable to both massive earthquakes and tsunamis, has long tried to minimize both the human and economic toll from massive waves. In 1983, it took 20 minutes for data to reach Tokyo about a big quake in western Japan.
By then a tsunami had already poured over sea walls, killing more than one hundred people on the Sea of Japan coast and causing 800 million dollars worth of damage. A decade later alerts could be sent within 10 minutes. But that was still not fast enough to save nearly two hundred people on the northern Japanese island of Okushiri in 1993.
Three minutes after a quake was felt, the island was hit by waves as high as 29 meters. Nobuo Hamada, an earthquake and volcano expert at Japan's Meteorological Research Institute says the 1993 tragedy mandated a new benchmark.
"Our target is we issue the tsunami warnings only three minutes after the earthquake."
Since then no one has died in a tsunami in Japan. The faster system is credited with saving lives in 1994 when a tsunami hit Hokkaido in northern Japan. Eight seconds after the tremor was detected, a warning was automatically sent via radio and television stations.
However, Mr. Hamada worries that developing countries do not have the resources for a system as elaborate as Japan's. He notes that despite initial enthusiasm for the Pacific tsunami warning system, some countries have been more motivated than others to take part in it and maintain the necessary infrastructure.
"Twenty-six countries around the Pacific joined. But actually the primary role is taken by United States. And Japan and several (other) countries (are) very eager to sustain it. But the activity of remaining countries is not so good."
Tsunami researchers warn, however, that state-of-the-art detection systems are useless unless information reaches areas at risk quickly and people know how to respond. The biggest challenge for developing countries may lie in ensuring coastal dwellers have enough radio or TV receivers to get the warnings or are within earshot of loudspeakers or sirens.
Coastal dwellers will also need to be educated about tsunami risks, so that when an alert is given, they know to head in-land. Ironically, many who survived the December 26th tsunami were considered the region's least sophisticated people. Sea gypsies and primitive tribes did not need technology to tell them that when the ground shakes or the tide suddenly recedes, it is wise to run to higher ground.
