TOKYO -- Japan's massive tsunami roared into the city of Sendai at around 15:53 p.m. on March 11, 2011, leaving devastation in its wake. Seaside houses and farmland were inundated within minutes; more than 15,000 were killed and thousands of others injured.
Reducing disaster risk has since become a major focus for companies. Tohoku University and Fujitsu Laboratories have jointly developed a real-time flood analysis system using Fujitsu's supercomputer, K. Its simulation model quickly calculates the estimated arrival time of tsunamis and the probability and extent of building damage.
The researchers believe the new system will lead to faster disaster warnings, helping people evacuate immediately and thus saving more lives.
When the earthquake struck on March 11, a lack of information on the scale of the incoming tsunami led to a sharp increase in the number of victims. TVs showed the coastal areas in the most danger, along the Pacific coast of Hokkaido and Honshu islands, in red. However, more detailed information -- how far the tsunami could reach and damage inland areas and how much time was left for people to evacuate -- was lacking. As a result, not a few local residents did not take the tsunami danger seriously and failed to evacuate to higher ground.
The new system automatically predicts and simulates models of tectonic shifts and sea surface deformation at the time of earthquakes, using relevant data. Then, it performs parallel computations using the supercomputer K to thoroughly estimate the tsunami's effects on areas. The K is capable of 10-quadrillion computations per second. It can figure out how far inland will be affected within 10 minutes of an earthquake.
In a test conducted earlier this year, researchers from Tohoku University and Fujitsu used data from the 2011 Japan earthquake to perform a tsunami simulation focused on an approximately 10-km area.
Based on the results, the team has created a hazard map. If the system had been in place back in 2011, local residents in the test area would have had 50 minutes to flee to safety.
Yusuke Oishi, a researcher at Fujitsu Laboratories who also serves as a project associate professor at Tohoku University, led work on the new system. He works closely with Professor Fumihiko Imamura, director of Tohoku University's International Research Institute of Disaster Science and an authority on tsunami engineering. Oishi has been able to shorten the time it takes for flood analysis, ahead of rival companies.
In February, he published an article on his research findings in the Geophysical Research Letters, a journal of the American Geophysical Union. He said he has received inquiries from overseas institutions after the release of his paper.
Work to be done
Fujitsu's supercomputer-based analysis system can be used in a number of circumstances. For example, Japan's Meteorological Agency, a government body, could adopt it for tsunami warnings.
Municipalities can also use it to provide disaster information to residents. But here, there are regulatory hurdles: Only the Meteorological Agency has the authority to release tsunami-related information.
To make it easier for municipalities to adopt its system, Fujitsu will have to develop software and offer cloud-based services.
Oishi expects that people will use the disaster analysis system through their smartphones and other devices in the near future. He said it could be ready for widespread use within three years.