Japan and Mexico have earthquake early-warning systems. How does California’s compare?

AdvertisementHe turned off the gas and quickly ran through his family’s whereabouts in his mind. He shouted to his daughter upstairs to make sure she was ready.

A few seconds later, the strong shaking arrived. The magnitude 7 temblor toppled a glass and swirled around the broth in the nabe dish he was cooking — but otherwise left most of his home, and nerves, intact. He and his daughter proceeded to sit down to dinner.

His nearly instantaneous reaction, built on a decade of experience, was second nature in a way it wasn’t in 2011, when his city was hit with the most severe earthquake in Japan’s modern history. At the time, he spent precious seconds wondering what that piercing sound was coming from his cellphone and those of his colleagues.

His phone’s alert is part of a nationwide earthquake early warning system Japan implemented in 2007 and has been improving ever since, a process that has involved devastating quakes, major false alarms and one of the most extensive public education campaigns in the country’s history.

Japan’s experience shows that getting the system up and running is only half the battle; the other half is getting the public to familiarize themselves with the alerts, what they signify and what to do when they receive them.

Uzurahashi, who had a friend who worked on earthquake warnings, said he was more aware of the system than the average person. Even so, the first few times he heard the alarm, he found himself disoriented and confused.

“Knowing about the system on paper is quite different from experiencing it,” said Uzurahashi, 63, a university administrator from Sendai, where more than 15,000 people were killed in the earthquake and tsunami in 2011.

“The first few years, nobody paid attention,” said Masumi Yamada, assistant professor at Kyoto University’s Disaster Prevention Research Institute, who has worked on technical improvements to Japan’s system since 2011.

A 2010 survey found that only half of those queried in the Tokyo metropolitan area said they were aware of the alerts and what they meant and less than 40% knew to anticipate that strong shaking was about to hit. That dramatically changed after the 2011 earthquake and the numerous aftershocks that followed. By the summer of 2011, 90% of those surveyed said they were aware of earthquake early warnings and their significance. Those who were completely unaware dropped to less than 2%, from 15%.

Once you experience, you will learn,” Yamada said. “It’s very hard to imagine something which has never happened.”Once you experience, you will learn. It’s very hard to imagine something which has never happened.”Masumi Yamada, assistant professor, Kyoto University Disaster Prevention Research Institute

The warnings remain popular in Japan despite false alarms and errors. In 2011, the alert underestimated the magnitude of the main earthquake and inaccurately forecast some of the aftershocks because some of the sensors lost power or misinterpreted data.

Mitsuyuki Hoshiba, an earthquake scientist with the Japan Meteorological Agency, which runs the system, said on about three occasions over the years, officials have had to apologize to the public for false alarms and explain what went wrong. The public seemed to understand and to continue supporting their efforts, he said.

“I think people think that even if it’s sometimes right, sometimes [an] over-prediction, it is much better than no information,” he said.

Tomomi Higuchi, a 40-year-old university employee and a colleague of Uzurahashi’s, recalled being on a business trip in Kobe with three students in the summer of 2013 when she received a warning for a 7.8 magnitude quake in nearby Wakayama prefecture. She ran out of the hotel and waited for the shaking to arrive. None came.

It turned out to be a magnitude 2.3 earthquake, misinterpreted due to inaccurate GPS data and time stamp. Trains were stopped, cellphone signals jammed and websites crashed. One official said it was “probably the biggest” misreading in the system’s history.