Millions of people in Japan were alerted up to a minute before the massive 9.0 earthquake reached them. Seismologists say the nation's billion-dollar earthquake warning system paid off by saving lives.
In Tokyo, there have been reports of trains that were stopped and assembly-line workers who took cover.
The warnings and a countdown clock were broadcast throughout Japan via television, radio and cellphone eight seconds after the quake was first detected.
Japan's warning system is the most advanced in the world. A network of seismic instruments detect initial tremors generated by an earthquake. These so-called p-waves race through the earth but cause little damage. The warning is sounded in the interval before more destructive, but slower-moving, tremors called s-waves arrive.
The U.S. Geological Survey wants to have a similar system for California. Seismologists have placed more than 400 earthquake monitoring stations around major faults, including the San Andreas.
UC Berkley seismologist Peggy Hellweg said earthquake data from the censors can be processed and sent out faster than the waves travel. She said when it comes to saving lives, every second counts.
“You can slow the trains down, you can’t stop them completely, but you can slow them down well in 30 seconds. You could have all the kids at the schools get under their desks. You could open the doors of the fire stations so even after the buildings have been deformed slightly the fire engines could get out,” explained Hellweg.
California’s $150 million warning system could be ready to test this year, but its federal funding is on shaky ground.
