Early warningEarly warning system helped save lives in Japanese quake

Published 16 May 2011

Japan has spent millions of dollars to build a sophisticated early warning system for earthquakes and experts say that it helped save millions of lives and mitigated the damage from the 11 March earthquake and tsunami; while the massive 9.0 magnitude earthquake and tsunami flattened much of northeastern Japan, the damage would have been far worse had Japan not had its early warning system in place; the system can provide anywhere from ten to thirty seconds of advance notice before an earthquake strikes giving Japan’s residents just enough time to slow down trains so they do not derail, shut off dangerous machinery, and send people to find cover

P-wave detection triggers notification system // Source: dailywireless.org

Japan has spent millions of dollars to build a sophisticated early warning system for earthquakes and experts say that it helped save millions of lives and mitigated the damage from the 11 March earthquake and tsunami.

According to Kunihiko Shimazaki, a seismologist and head of the Japanese government’s earthquake prediction advisory board, while the massive 9.0 magnitude earthquake and tsunami flattened much of northeastern Japan, the damage would have been far worse had Japan not had its early warning system in place.

“I think it saved many people,” Shimazaki said. “Particularly with the tsunami warning, it gave people time to act.”

Depending on where the earthquake’s epicenter is located, the system can provide anywhere from ten to thirty seconds of advance notice before an earthquake strikes. While that may not seem like a lot of time, it gives Japan’s residents just enough time to slow down trains so they do not derail, shut off dangerous machinery, and send people to find cover.

On 11 March, after Japan’s sensors picked up that an earthquake was about to strike, an alarm interrupted television programming in Tokyo, 230 miles from the epicenter, ten seconds before the shaking began.

 

Roger Musson, a seismologist at the British Geological Survey, said those ten seconds made a valuable difference.

Ten seconds is time to turn the gas off if you’re cooking, and that could make all the difference between your house burning down or not,” Musson said.

To develop this advanced warning system, Japan spent an estimated $500 million to install a sophisticated network of sensors that can detect when an earthquake’s initial vibrations, called “P waves,” hit. P waves do not cause a lot of shaking, but these initial tremors travel much faster than the deadly seismic activity which follows closely behind.

Japan initially launched this system in 2007 making it the first in the world.

Despite the early warning sensor’s success in the last earthquake, Shimazaki says that the system still has problems.

During the 11 March quake, many of the sensors were quickly taken offline by the tremors or the tsunami waves. In addition, because of the enormous magnitude of the earthquake, the remaining sensors were overloaded with data making the results difficult to interpret.

Shimazaki said, “There were some really simple problems that need to be fixed.”

He added that he and his fellow researchers are developing methods on increasing protection for the sensors and a better means to interpret data.

We are gradually getting to a point where we can understand things much better,” he said. “We have many things to reflect on, and regrets about things that we might have done differently. But our role is to see that improvements are made.”